I just bought the Asus TOP version, 55nm, overclocked loads from Overclockers for 129. It was made at the beginning of this month, that's how new it was, I figured it would be old stock. It comes with the stock cooler but the rear of the pcb has a metal faceplate which acts like a heatsink. It was between that or the Gainward for 3 quid more which had a nice cooler but wasn't clocked so highly.
I replaced a 4870 512mb, and as I am at 1920x1200 and the 4870 didn't have enough memory for that really, I am seeing between 5 and 20 more fps in various games.
This is what it clocked too stabily too.

The only game its not too great with is Arma 2, but that is the game not the card as a GTX285 doesn't doo much better than mine at the moment till issues are sorted by the developers.
Also gets 45 fps with everything it will let me turn up in GTA4, a full 18 fps more than with the 4870. It also laughs at Crysis Warhead.
My CPU is a Core i7 920 though.
The reason I am using what seems to be an old driver is if you use anything later in Arma 2 it (the game) defaults to 256mb vram and the game runs like a turd.