These are nice cards. I have one that has been folding for a few days now at 721/1836/1600 with no problems. I used the ASUS Smart Doctor for overclocking.
According to Fahmon it's at pace for 3850 ppd on WU 5757.
I have an Antec 300 case and I installed the optional twin 120mm intake fans, but I left the side fan out so that is just open.
This ASUS card is running at only 54 C even overclocked like it is.
Also note this ASUS card seems to have an extra voltage regulation power phase compared to EVGA and other brand cards I have seen.
Look at the picture with the heatsink removed here:
http://www.digital-daily.com/video/asus_en8800gs/
See the 4 large gray things to the right of the memory chips? Most 8800GS or 9600GSO cards have 3.
I believe that having 4 means it has 3 phase power. One of them is for the memory, for the 4th.