Oh yeah the 5970 is beast! Of course, make sure your case can fit it. Fortunately, you don't have to worry as much about keeping your room ventilated with the 5000's :P
problem is that they are a bit harder to find right now. I'd have gotten one, but my case is too small for it unless I install a water block, since the lowest part of the stock heatsink would bump into my hard drive cage
Lol, if they ever release a 495, I bet it gonna cost at least 800. :o