FWIW, I'm clocking about 500MHz faster (READ: STABLE) on a new board.
P5W-DH Dlx - Q6600 G0 @ 3.15GHz
P5K Premium - Q6600 G0 @ 3.6GHz
Both of those are with the EXACT same RAM, HSF (TR Ultra X-120), thermal paste, case, HDDs, video card - the works. All that changed was the board.
Both are Prime95 multicore stable for 48 hours. On the P5K I can boot at 4GHz (but not stable).
I loved the old P5W DH, but I had a really early version that only did up to 1.65V on the MCH, and it was REALLY holding the chip back.