toyota
Lifer
if you are able to overclock a 5850 high enough to beat a gtx480 then the power consumption and resulting heat would be just as high anyway.I'd take a 5850 over 470 any day. The room I game is in already quite warm in summer. An overclocked 5850 will probably give you near 480 performance, maybe faster.
That's not to say the 470 is a bad buy, depending on your circumstances, budget, and performance goals it may be the best choice. It may not. I think the 5850 trumps it (and the 5870 and 480) in bang for the buck.