I have the card, though I haven't been "testing" it out extensively (classes getting in the way).
It is definitely very quiet, having no fan will do that.

Temps I've gotten were 54 idle and 68 load using rthdribl, with the pipes and shader unlocked. Tried a little overclocking but didn't push it much.
Can't really say much else. It worked perfectly for me right out the box and I think it could overclock decently if I sat down for a bit and tried it. So far I've been playing UT2k4 and Call of Duty at 1280x1024 (maxed settings) and it's been blazin'.

At least, compared to gaming on my laptop, which is beat by pretty much anything these days.