I lapped my Ultra Extreme too.
I didn't do the IHS on my E6750, but my temps are so awesome I didn't need to. I'm idling at 28C right now with 1.5v and a 933Mhz overclock. I think my temps top out at around 50-52C under dual prime95.
I could probably squeeze another 200Mhz out of this thing if it wasn't for the "vdroop" problem. I'm just not comfortable running this chip at 1.55v or higher to compensate for the voltage drops under load.