@Emu: Did you notice that in the last pic on your post #223, CPUZ shows 860 Vcore = 1.096V @ 4095 MHz. But the max core temps are up around 70deg, which is what you'd expect with 1.4V. Must be a CPUZ error (?)
Any thoughts on why your 860 seems a bit slower than the 920, while 123bob found the opposite?

Re. power consumption: The extra Vcore needed on your 860 seems to be making it run about the same max temps as the 920. If they have the same cooling, that would mean the same amount of heat energy coming out, ie same CPU power in. Other relevant info: A few days ago I read a review where they got an estimate of the mb power consumption and figured the X58 chip was causing their 920 board to use about 20W more than their P55 one.
If you get a 2nd power meter, it would be a good idea to check them against each other.