Ok, here are my thoughts on what we have established in this highly unscientific discussion:
E92 M3 6MT runs pretty even with 404ps C6 vette beats it on track, handling etc.
E92 M3 6MT loses to LS3, Z51 in all disciplines
E92 M3 DCT might run the above close on acceleration (depends on how good the box turns out to be) but most likely will lose on track (still a softie)
E92 M3 CSL DCT would most certainly whip all vettes bar ZR1 (Z51, LS3 and Z06) on track. It would be interesting to see how it copes with the Z06 in acceleration tests.
btw here is something that would put them all to bed