The PS3 has untapped potential as far as filesize is concerned. So much data can be stored on one of those little blu-ray discs that it may be hard to find things to put on them. As of right now, XBox has the better games, but I believe with time the PS3 will update some of their exclusive titles. As far as GTAIV is concerned, both versions will be of the same graphical quality, but the XBox will have additional episodic content. So I say, even though I own a PS3, you may enjoy the XBox more.