Well it's actually on my E8400. The DK is still cooling the Q9450 alright. I may one day put the 212 in my main rig but as of right now it's too much of a hassle since I wouldn't OC the Quad anyways.
Anyways, I've got some results:
E8400 @
2.0GHz w/ horrible stock cooler
Idle avg - 47C
Max load (BOINC) - 66C
E8400 @
3.0GHz w/ Hyper 212+
Idle avg - 35C
Max load (10 Prime95 iterations) - 42C
So as you can see, there's a friggen huge difference. The 3GHz run with a more intensive stress test didn't even bring it to the old 2GHz idle temp. Now don't think all Intel stock coolers are this bad (although they may be). Mine had an uneven base do to a tardnugget lapping attempt.
Here it is. I didn't want to have to mount it that way but the NB heatsink wouldn't allow it to go vertically.
http://img833.imageshack.us/img833/9394/21212121.jpg
Very satisfied overall. Big thanks goes to Cecil for hooking me up with it for a great price.
I will try to get a good OC on it as soon as I find out what's cockblocking every overclock on every Intel CPU I've ever used. I'm missing some option that needs to be enabled, disabled, or changed. But, that's a story for another post.