I agree with alms211 synopsis - I owned a 2007 Corvette Z51 6MT prior to my 2008 M3 6MT and have driven all different versions of the C6. Overall the M3 is a better car, but the Corvette is an thrill ride.
The gearing on the cars and the power delivery is so incredibly different they are hard to compare in terms of power and speed. From the seat of the pants test, I would tell you that I believe even a 400hp LS2 Corvette would pull from my 08 M3 6MT. In actuality it would probably be a toss up. With all the torque, the Corvette just hits you harder.
Btw, I absolutely love my M3 but there are some times when I miss the Vette