So I just finished installing Vista 64 and while it was installing I took the time to read a few reviews and investigations into DX10 32bit vs 64bit Crysis at "very high." I've yet to get Crysis installed on my 64bit partition but now I think I'm just going to put it on hold as there does not appear to be any benefit at all to going 64bit in crysis.
A few people are reporting that the game "feels smoother" but the numbers seem to indicate that the FPS are exactly the same. Does not seem worth the trouble. Probably should of read a bit more before taking the time to install Vista 64. On the other hand, I'm sure I'll use it in the future..