I played the xbox version and the PS2 versions at the Acclaim booth the E3 they showed it (with a few other stinkers..) and the Xbox version was MUCH better. The PS2 version suffered from bad frame-rate, long loads and low rez textures. I hope the PS2 version is much better now.
I have the Xbox version and it is a great game, simple button mashing shooter, reminds me of Cannon Spike, much longer but not as good overall.
I will pick it up for sure!