When inflating a bicycle tire is CO2 better than normal air Why What would be faster?

Assuming the choice is between a CO2 cartridge inflator or a regular pump, then the CO2 is faster. If the choice is between a CO2 cartridge inflator and a stationary air compressor then it's no difference. The tube/tire doesn't really care which to any important amount, as long as you're not overinflating.