I lapped my QX6700 today. Temps have come down a few degrees which is great, but temps between all 4 cores is very even now under load.

I also rotated my NB heatsink 180 so the pipes are over the NB chip, and put an 80mm fan blowing up aswell. It's really made no difference. On load the NB temp is still just over 80degrees

However I put a 70mm fan over the PWM heatsink so that would of made a good different Im sure as that was too hot to touch before.