I am one of those people who has an ATI 5800 2GB video card and could never play Rage. I stopped trying to get it to work but now notice I can play, probably to do with the automatic video driver updates.
What I do notice now that in the game, I am only at the beggining, is that there are no details to the floor, walls or desert landscape. They just appear as formless objects. People and cars have details.
Any ideas?