They are about the same. they will trade blows on games and pretty much everything. The 570 is slightly faster, but with less bandwidth and less memory. Really, the 570 is just the refined 480, but the 480 is cheaper. It is as posted $200 and should kick the ass of any newer card at $200
Yea, in the same price range your looking at a 7770 GHz or 6950 and it should beat the first and beat the second, but not by much. Might loose to it, not sure. But I would definitely go for the 570 or 480 over any AMD card if you do anything other than gaming.