I've got one and am very happy with it.
Wierdly, I've found that overvolting the chipset can actually have a negative affect on the maximum overclocking limit. I've read that some others have found the same thing.
The nVidia chipset does seem to run very hot normally (40-50C), and the supplied chipset cooler seems small for the amount of heat it has to deal with. Maybe I should try adding the chipset into my existing watercooling system (thats currently just doing the CPU and two 8800GTX's).