I really can't understand how so many can NOT notice the tearing on the 360. I don't own a PS3, but the problem seems to exist there as well.
It seems that most console gamers are very easily pleased... Maybe that is because the gaming background of most comes from last gen consoles, and the increased (though usually not quite HD) resolution is still enough for them to be wowed.
I can only guess, but I think most gamers with a PC gaming background have way higher standards regarding image quality. I enjoy playing games on my 360 when i want to game from my couch, but the terrible tearing (I remember it being really bad in Gears of War), lack of anti aliasing and framerate problems in almost every graphic heavy game really piss me off sometimes.
