Go and play the following games side by side, these are just the ones I have 1st hand experience of:would disagree with you i have had no run issues with any of my PS3 games and i have said that PS3 versions look better, and the Playstation store/network is far easier and better than the marketplace on the 360
Rainbow 6 vegas
Skate
Fallout 3
The Orange Box
GTA4
Assasins Creed
The frame rates, graphical touches (such as antialiasing) and lighting effects (n ot necessarily all things for all games, but i cba to be that pedantic) are significantly poorer on the ps3.