Oh yeah, forgot about that. I think I am right in saying that the Q6700 is a G0 stepped processor, whereas the QX6700 isn't. The QX6700 of course has the unlocked multiplier, but the Q6700 wouldn't need it as much since I maintains lower temperatures. It all depends on what your current clock is really, so what is it ?

EDIT: are you getting the asus maximus extreme at the same time as the processor?