IGN reported in there video head to head that On the Xbox and Gamecube version there were only 3 turbo buttons L, R, and Left thumbstick and L, R, and Z respectivly, which lead to less control over which turbo move you pulled off. That was my only concern.
Great question, I would prefer the xbox version because of the better load times and 4 controller support but the fact that the game only has 3 turbo buttons with an xbox controller made it a definite no when compared to the ps2 version.