Here's a direct comparison -
http://metku.net/index.html?path=rev...-gts/index_eng
Personally, given the prices I saw back in early January, the 8800GT was the winner, hands down. Very little performance difference between the two cards, but a big price difference. And my 8800GT has had no heat issues at all - single slot form factor seems to be just fine. Mine only has 512MB RAM - of course, the NVidia drivers will use some of my 4GB system RAM as well, if needed (the graphics system actually "sees" it has over 1.5GB available on my machine, 512MB dedicated on the card itself, plus shared system RAM as needed).