I agree with smp...I think that if you get the process down pat, that you must still provide ALL the different CPUs you can to fill the needs....hence the nice OCn on the 600.
My Duron600 is running at 10x105 for 1050...not bad.
But I do have the taisol742 w/27cfm fan, lapped with 2000 grit, and Arctic Silver with 1.9v....
Never seems to get hotter than 93f.