Hey, thought I would chime in with my experiences as well.
I'm currently running my 3000+ at 2.25Ghz
250 FSB
4x HTT
ram at 533-4-4-4-12-2t@1.95V
PEG link disabled
PCIE clock set to 100Mhz
No stability issues, no problems at all except for the soft reboot problem at this speed. I am almost certain that this CPU has more to give, and it's just being held back by the board.
As far as the vDIMM issue - it's really irritating. I know (because of AI Booster) that this board will do over 1.95V, and what's irritating is that they don't release a BIOS that addresses the real issue with this board. It probably takes them all of three minutes to add the extra options on the vDIMM and they won't do it.
Oh, and as I wrote this I remembered hearing something about higher overclocks/stability being achieved when the PCIE clock was set to 110 (I think - and this is from what I remember, which usually isn't a whole lot, lol). This could have been with the K9N (which I wish I would have stuck with), but maybe someone wants to try it and see what happens? I would try it, but I'm done messing with this board until the vDIMM issue is fixed.
Oh, and I'm not recommending overclocking, I'm not responsible for you messing anything up if you set your PCIE clock too high, etc.
Forgot to mention, I'm using Gskill DDR2-667 - 2x1GB