According to IGN, the PS3 version of Tony Hawk's Project 8 suffers from two key problems. First, as previously announced, the PS3 version lacks an online mode. However, more suprisingly, the PS3's Project 8 frequently grinds to halt. The game chugs and the framerate frequently drops to an unplayable 15 FPS.
To sum it up, IGN says "It's certainly disappointing that the PlayStation 3 is so far behind the Xbox 360 game. Framerate issues are apparent at every other turn, and the lack of online play really hurts. Project 8 is a worthy game to pick up, just preferably not on this system."