Attachment variety & compatibility the c3 cat-and-dog is the only c3 to come with a handheld mini turbo brush
Cord management they all have the one touch automatic cord rewind foot pedal
Dust-bin capacity they all use the same filter bag with the same 4.5 litre capacity
Noise level they all have the silent system with a noise optimized motor and integrated sound insulation
Odor control / carbon-filter effectiveness the cat and dog is the only c3 that uses an active air clean filter which includes active charcoal for odors
Status indicators (battery, bin, filter) they all have an indicator to let you know when that bag is full
Suction power (air watts) they all have the same 1200 watt motor and should technically have the same suction and air flow power specifications