I donno about a C6, but I know for a fact its faster then the RB S5,

I tested 2 GO R-specs up to the S5, even the owner of the S5 says he loves the S5 but the R-specs are faster.

Now what sucks with the R-specs are the carbs, they are crap, reminds me of picco carbs. And the r-spec stock rear bearing isn't that great.