Average score
Product 1: GravaStar Mercury V75 Pro
4.1
Product 2: Keychron K4 HE
4.3
acoustics
Product 1: GravaStar Mercury V75 Pro
4.2

Reviewers describe the sound as clacky and generally pleasing, with one noting it is louder and more direct while others call it clean or good sounding.

Product 2: Keychron K4 HE
4.6

Multiple reviewers praise the K4 HE’s sound, describing it as marvellous, thocky, or simply nice, with little rattle mentioned.

actuation consistency
Product 1: GravaStar Mercury V75 Pro
4.4

Actuation and switch behavior are consistently portrayed as precise and responsive, with stable performance, accurate registration, and rapid actuation/deactivation noted across multiple reviews.

Product 2: Keychron K4 HE
4.7

One review explicitly describes the magnetic switches as consistent and responsive in action.

analog input support
Product 1: GravaStar Mercury V75 Pro
No score yet
Product 2: Keychron K4 HE
4.8

Reviews consistently note analog-style input support, including gamepad or joystick emulation and variable control based on key depth.

backlight brightness
Product 1: GravaStar Mercury V75 Pro
4.6

Brightness is strong where discussed, with reviewers calling the RGB bright and highlighting brightness controls in the web driver.

Product 2: Keychron K4 HE
2.5

One review says the backlight is too dim to see well in daylight.

battery life
Product 1: GravaStar Mercury V75 Pro
No score yet
Product 2: Keychron K4 HE
4.4

Battery life is generally viewed as good, with evidence citing roughly 100 to 110 hours, though one reviewer notes stronger battery life exists elsewhere.

build quality
Product 1: GravaStar Mercury V75 Pro
4.6

Build quality is one of the keyboard's strongest areas, repeatedly described as sturdy, heavy, well-built, high quality, and aluminum-based.

Product 2: Keychron K4 HE
4.7

Reviewers repeatedly describe the board as sturdy, solid, or premium-feeling, with little or no flex reported.

cable quality
Product 1: GravaStar Mercury V75 Pro
2.2

The included cable is a weak point in the one review that discusses it, because it is a plain rubber USB cable rather than a braided cable.

Product 2: Keychron K4 HE
3.2

Cable feedback is mixed: reviewers like the included cable quality or angled design, but several also call it short.

compatibility
Product 1: GravaStar Mercury V75 Pro
4.0

Compatibility is generally positive for keycaps, Windows/Mac use, and select magnetic switch replacements, though switch compatibility still requires checking supported TTC and Gateron models.

Product 2: Keychron K4 HE
4.8

Reviews say the K4 HE works across Windows and macOS, and one review also mentions Linux support.

connectivity
Product 1: GravaStar Mercury V75 Pro
2.2

Connectivity is limited because the keyboard is wired-only; reviewers treat the wired setup as functional but restrictive.

Product 2: Keychron K4 HE
4.8

Multiple reviews confirm wired, 2.4GHz, and Bluetooth support, with easy switching and multi-device use.

customization options
Product 1: GravaStar Mercury V75 Pro
4.5

Customization is broad, especially around actuation, rapid trigger, lighting, remapping, profiles, and Hall effect features through the web-based driver.

Product 2: Keychron K4 HE
4.8

The K4 HE offers unusually deep customization in the evidence, especially around per-key actuation, remapping, and gaming settings.

desk space efficiency
Product 1: GravaStar Mercury V75 Pro
4.1

The 75% layout saves space versus full-size boards by dropping the numpad and full navigation cluster while retaining arrows and useful keys.

Product 2: Keychron K4 HE
4.8

The 96% layout is repeatedly framed as saving desk space while keeping most of a full-size board’s utility.

durability
Product 1: GravaStar Mercury V75 Pro
4.5

Durability evidence is positive, with reviewers pointing to heavy-duty construction, high-quality materials, and long switch lifespan claims.

Product 2: Keychron K4 HE
4.9

One reviewer reports the board survived a coffee spill and kept working afterward.

ease of switch replacement
Product 1: GravaStar Mercury V75 Pro
4.7

Switch replacement is easy where discussed, because the Hall effect switches are hot-swappable and do not require soldering.

Product 2: Keychron K4 HE
3.3

Switch swapping is possible, but replacement is constrained to specific magnetic Gateron HE options.

ergonomics
Product 1: GravaStar Mercury V75 Pro
4.1

Ergonomics are helped by adjustable feet or folding legs that change typing angle, though one reviewer found the feet visually unusual.

Product 2: Keychron K4 HE
4.2

Ergonomics come across as decent thanks to angled rows and a posture-friendly typing stance, though nothing suggests a low-profile feel.

extra gaming features
Product 1: GravaStar Mercury V75 Pro
4.6

Extra gaming features are a major strength, with rapid trigger, SOCD/LKP, DKS, mod-tap, profile switching, and advanced Hall effect functions cited.

Product 2: Keychron K4 HE
4.8

The review set repeatedly mentions quad-actuation, Snap Tap or LKP, dynamic keystrokes, and similar Hall Effect gaming extras.

frame rigidity
Product 1: GravaStar Mercury V75 Pro
4.6

Frame rigidity is strong, with reviews emphasizing a heavy-duty aluminum or metal case, sturdy feel, and high-quality construction.

Product 2: Keychron K4 HE
4.8

Reviewers report no body flex and very stable behavior on the desk.

gaming performance
Product 1: GravaStar Mercury V75 Pro
4.5

Gaming performance is consistently rated highly, with reviewers reporting smooth play, strong FPS performance, no obvious performance complaints, and fast response.

Product 2: Keychron K4 HE
4.8

Across shooter and general gaming use, reviewers consistently describe the K4 HE as fast, capable, and competitive.

hot-swappable switches
Product 1: GravaStar Mercury V75 Pro
4.6

Hot-swap support is clearly present where reviewed, letting users swap compatible magnetic switches without soldering.

Product 2: Keychron K4 HE
3.9

The switches are hot-swappable, but that advantage is limited by the restricted switch ecosystem.

keycap quality
Product 1: GravaStar Mercury V75 Pro
4.0

Keycap quality is mixed: several reviews praise the PBT/PC materials and durability, while Tom's Guide strongly disliked the rough paint-like texture.

Product 2: Keychron K4 HE
4.6

Reviews praise the included PBT or OSA keycaps for feel, shape, and durability cues.

key responsiveness
Product 1: GravaStar Mercury V75 Pro
4.5

Key responsiveness is a major strength, with reviewers describing instant key presses, feather-touch activation, ultra-fast response, and rapid registration.

Product 2: Keychron K4 HE
4.8

Magnetic switches are consistently described as quick to register and helpful in fast gameplay.

key spacing
Product 1: GravaStar Mercury V75 Pro
4.3

Key spacing and navigation are mostly positive, with reviewers finding arrows and extra keys easy to locate and useful in the 75% layout.

Product 2: Keychron K4 HE
2.9

The condensed 96% layout is the most common complaint, with several reviewers calling the keys cramped or easy to mis-hit.

key stability
Product 1: GravaStar Mercury V75 Pro
4.6

Key stability is directly praised in one review, which notes stable switches with minimal wiggle or wobble.

Product 2: Keychron K4 HE
4.6

Double-rail magnetic switches are credited with reducing wobble and improving key stability.

latency
Product 1: GravaStar Mercury V75 Pro
4.4

Latency performance is strong across gaming-focused reviews, with several noting no lag, low latency, or very fast measured results.

Product 2: Keychron K4 HE
4.1

Latency is generally strong for the category, though some evidence says it is not class-leading.

layout options
Product 1: GravaStar Mercury V75 Pro
4.1

Layout options are solid around the 75% form factor, variants, and configurations, though users wanting larger boards or numpads may still be limited.

Product 2: Keychron K4 HE
No score yet
legend visibility
Product 1: GravaStar Mercury V75 Pro
4.4

Legend visibility is positive where discussed, with one reviewer noting the large themed legends remain very legible.

Product 2: Keychron K4 HE
3.3

Legend visibility is mixed: one review praises clear legends, while others note non-shine-through caps and harder-to-see lighting on the Special Edition.

macro customization
Product 1: GravaStar Mercury V75 Pro
3.2

Macro customization is mixed: one review says the web software can record macros, while another found no macro recording function at the time of testing.

Product 2: Keychron K4 HE
4.8

Reviews confirm robust macro support, including complex macros and flexible mapping.

materials quality
Product 1: GravaStar Mercury V75 Pro
4.5

Materials quality is high, with repeated references to aluminum alloy, metal, full aluminum case construction, and sturdy high-quality materials.

Product 2: Keychron K4 HE
4.3

Materials get mixed-positive remarks: aluminum framing and real wood accents add quality, while some plastic remains in the shell.

media controls
Product 1: GravaStar Mercury V75 Pro
4.1

Media controls are present through a volume knob or lever, including mute behavior, though it is not always a traditional rolling knob.

Product 2: Keychron K4 HE
3.6

Media controls are available through FN combinations rather than dedicated keys.

noise level
Product 1: GravaStar Mercury V75 Pro
4.0

Noise level leans clacky and noticeable rather than silent, but reviewers generally describe the sound as acceptable or good rather than harsh.

Product 2: Keychron K4 HE
4.5

One review specifically says the switches are not very loud.

onboard memory
Product 1: GravaStar Mercury V75 Pro
4.0

Onboard profile support is only lightly evidenced, with one review mentioning onboard presets and profiles.

Product 2: Keychron K4 HE
4.8

Reviews confirm onboard memory for saving settings or profiles on the keyboard itself.

per-key lighting control
Product 1: GravaStar Mercury V75 Pro
4.6

Lighting control is strong, with per-key RGB, backlighting, side lighting, and lighting controls noted across reviews.

Product 2: Keychron K4 HE
2.0

One review explicitly says there is no per-key lighting customization for custom colors.

polling rate
Product 1: GravaStar Mercury V75 Pro
4.4

Polling rate is a high-spec strength, with multiple reviews citing or testing 8,000Hz polling, though one reviewer considered it more marketing than noticeable.

Product 2: Keychron K4 HE
4.5

Polling rate is consistently cited at 1,000Hz, which reviewers view as solid for the price but not top-tier.

portability
Product 1: GravaStar Mercury V75 Pro
2.6

Portability is a weakness because the board is heavy, wired-only, and visually or physically bulky despite its 75% layout.

Product 2: Keychron K4 HE
4.5

One review highlights the relatively light weight and says it is easy to carry in a backpack.

profile management
Product 1: GravaStar Mercury V75 Pro
3.9

Profile management is supported through presets and easy profile switching, though some layer behavior was described as limited or imperfect.

Product 2: Keychron K4 HE
4.6

Reviews mention multiple saveable profiles, typically three, for work and gaming setups.

rapid trigger support
Product 1: GravaStar Mercury V75 Pro
4.7

Rapid trigger support is a core strength, appearing repeatedly with fine adjustment ranges and advanced Hall effect behavior.

Product 2: Keychron K4 HE
4.8

Rapid Trigger support is a core selling point across the review set and is repeatedly described as useful for fast inputs.

reliability
Product 1: GravaStar Mercury V75 Pro
4.2

Reliability is generally positive where discussed, with the keyboard feeling durable and a reviewer reporting no major issues, though minor double-clicking was noted as fixable.

Product 2: Keychron K4 HE
4.8

Reliability evidence is positive, with one reviewer expecting years of use and another reporting no issues after a spill.

RGB customization
Product 1: GravaStar Mercury V75 Pro
4.5

RGB customization is extensive, with web software controls for lighting effects, colors, brightness, side lighting, and custom lighting behavior.

Product 2: Keychron K4 HE
4.5

Lighting customization includes selectable effects and colors, though the evidence does not show full per-key color control.

RGB lighting quality
Product 1: GravaStar Mercury V75 Pro
4.6

RGB lighting quality is a standout feature, with praise for underglow, side lighting, bright effects, leg lighting, and the visual glow through translucent keycaps.

Product 2: Keychron K4 HE
4.2

RGB quality is mixed: some reviewers call it vibrant or solid, while others say the Special Edition lighting looks subdued.

size and form factor
Product 1: GravaStar Mercury V75 Pro
4.0

The 75% form factor is generally practical, balancing desk space and function keys, but some users may prefer smaller travel boards or larger layouts.

Product 2: Keychron K4 HE
4.7

The 96% form factor is repeatedly framed as near-full-size functionality in a smaller footprint.

software quality
Product 1: GravaStar Mercury V75 Pro
4.2

Software quality is mostly positive because the web driver is easy and feature-rich, but some reviews mention early quirks, language issues, or missing macro support.

Product 2: Keychron K4 HE
4.5

Keychron Launcher is widely praised for being easy and flexible, though several reviews note that changing settings usually requires a wired connection and one calls the UI cluttered.

sound dampening
Product 1: GravaStar Mercury V75 Pro
4.4

Sound dampening is well supported by foam layers, dampening pads, and case design that reviewers connect to a cleaner clacky sound.

Product 2: Keychron K4 HE
4.7

Several reviews mention foam, acoustic pads, or low rattle, suggesting effective sound dampening.

stabilizer quality
Product 1: GravaStar Mercury V75 Pro
4.5

Stabilizers are positively described in the reviews that mention them, with reduced rattling/pinging and good stabilizer sound.

Product 2: Keychron K4 HE
No score yet
switch feel
Product 1: GravaStar Mercury V75 Pro
4.4

Switch feel is generally praised as light, smooth, stable, and pleasant, though switch choice is limited to linear Hall effect options.

Product 2: Keychron K4 HE
4.3

Switch feel trends positive overall, with reviewers calling the magnetic switches airy or satisfying, though one found them too soft for typing.

switch options
Product 1: GravaStar Mercury V75 Pro
2.6

Switch options are limited, especially for stock switch choice and for users who want tactile or clicky switches rather than linear magnetic switches.

Product 2: Keychron K4 HE
2.7

Switch choice is limited, with several reviews noting support only for specific double-rail magnetic switches.

typing comfort
Product 1: GravaStar Mercury V75 Pro
4.2

Typing comfort is decent to good: reviewers liked the light switches and daily-use feel, though some disliked keycap texture or sensitivity settings.

Product 2: Keychron K4 HE
4.7

Typing comfort is generally good in the evidence, with comfortable profiles and approachable feel once acclimated.

typing feel
Product 1: GravaStar Mercury V75 Pro
4.1

Typing feel is generally good or smooth, helped by light switches and sound tuning, but not every reviewer considered it great due to keycap texture or sensitivity.

Product 2: Keychron K4 HE
4.4

Typing feel is mostly praised for sound and smoothness, but one reviewer found it sloppy for typing out of the box.

value for money
Product 1: GravaStar Mercury V75 Pro
3.6

Value for money is divisive: several reviewers find the premium build and design worth it, while Tom's Guide and another reviewer argue cheaper competitors offer better value.

Product 2: Keychron K4 HE
4.7

Value is one of the clearest strengths, with multiple reviews explicitly calling the K4 HE well-priced or high value for its feature set.

volume control
Product 1: GravaStar Mercury V75 Pro
4.1

Volume control is useful and repeatedly noted, using a knob or lever that can adjust volume and often mute.

Product 2: Keychron K4 HE
3.0

Volume control exists through function-key shortcuts rather than a dedicated knob or wheel.

wireless performance
Product 1: GravaStar Mercury V75 Pro
1.4

Wireless performance is a clear weakness because the keyboard has no Bluetooth or 2.4GHz wireless mode and is wired-only.

Product 2: Keychron K4 HE
4.7

Wireless use looks strong in the reviews, with easy multi-device use and quick wake behavior.