Is a system with more capacity better?Updated 9 months ago

No, a larger system with more capacity delivers less comfort and costs more to operate. 

A non-inverter central air conditioner is at its least efficient when first turning on. A system with too much capacity will run in numerous short cycles, turning on and off repeatedly, thereby causing it to be less efficient. 

Also, keep in mind that an air conditioner only removes humidity when it's running, so a system with shorter run cycles doesn't remove humidity from the air very well, which will cause an excess of humidity in your conditioned space.