is c320 much faster than c230 ss ??

its slightly faster..For some people, simply having a v6 means alot..

i got a c320 for a loaner one time and there was a difference, but not a BIG difference. to tell you the truth, i enjoy the supercharger a lot. the sound is great, and you can feel it. this kid in my school has a slk320 and we raced, and his far seemed much faster. maybe the torque and i'm guessing his car is lighter?

You can notice the difference on higher speeds. But on legal speeds the difference is quite marginal.