all the games u mentioned above was originally designed for the xbox 360 then copied to the PS3.. that's why they get Higher score & face some issues on the PS3..
if they design the game on the PS3 then move em to XBOX 360.. they won't work..
so they have to limit the game to the xbox engine.. coz the PS3 can handle anything..
GTA4 producers said that they had to cut alot from the game so they fan make it fit the xbox 360..
the xbox 360 won't be able to survive this console wars for another 2 or 3 years..
PS3 will live till they invent something better than Cell Processor & Blue Ray driver..
when will that be..?!?!