gpu temp is prob higher
but our cards are lacking not because of heat but because of their architecture which is the 0.11 micron core which needs less volts to run. imo.
if temp was the prob i would have cranked it up to 600 +
with dry ice on top lol.
but imo there is only a limit to how much OC you can do on specific volatages.
also i bet you can easily increase you memory clock.
try it out, i was stuck at the 510 range for a bit then for some reason it let me go to 552.
my gpu temp is around 41 idle with case closed and about 37 with case open. the environment temperature is a bit lower on both.