I just installed the CNPS7000-CU in my pentium 4 2,4 system. Here are some impressions:
Very easy. Opening the package it came is was the hardest thing. Screwing the cooler onto the clips that came with it was done in under a minute.
On my 2,4ghz@2,89 the processor temp is about 55 degrees celcius under load. When the fan speed is set to max it lowers to around 52-53. Before with my CNPS6500B-ALCU it could go up to over 60 degrees in silent mode!
None. It's even more quiet than the 6500. And the full speed mode isn't nearly as noisy as the 6500 fan at full speed.
Go buy it now. It should be out 'cause I bought mine from a local retailer today.
The only thing that worries me is how are you over clocking... over volting as well or at stock voltage? (It makes huge difference in wattage consumption of processor).
I am moving to P4 3.06 pretty soon and I think it will probably generate a little more heat than your rig if this is done using stock voltage. Which brings it to 55+ C in silent mode. (I believe junction in P4 3.06 is rather low at 69C which doesn't give as much room for failure) (My guestimate would be 57-58 under load with the setup)
Also, I would like to get description of your airflow in case... Do you consider it to be excellent? good? okay? or so-so?... (I noticed compared to my previous case vs current one, the temp difference is as much as 3-5c on CPU)
Right now, my 80mm vantec cooled Zalman 5700Cu running at 1250 RPM keeps 2.53 undervolted to 1.325V at 49C under full load. I wonder if 5700Cu is more efficient or less efficient compared to 6500Cu so I can get better idea on 7000....
(or SLK900 would be ultimate choice?)