This was more of a side grade for me, I wanted to upgrade my wife's rig to duel core (or rather, it seemed like a good idea with these so cheap!) so instead I sent the manchester 3800+ over to her PC and put this in mine.
10-12 hours duel prime stable at 2500 and some change mhz, 1.35v. I backed it off to 2500 even for daily use. Runs a lot cooler then the manchester...seemed to be topping out at 43c whereas the manchester ran low 50c IIRC. I did have the door off though.
Oh, btw. I had instant prime fail at 2640mhz and default volts (1.35v) and 1.375v. I could probably squeeze more out of this guy without to much trouble but 2.5 is good enough for me.