I refuse to use any Zalman cooling solutions. There are a number of reasons:
1.) they weight way to much! The 7700 CU is 850 some grams, and the max weight limit for both A64 boards and P4 board is.....(drumroll) 450g! This can cause serious problems when you move sour computer. (think 850g hanging off the PCB of your mobo, wouldn't you be worried that you'd move it the wrong way, and break a few of the very delicate traces?)
2.) you have to change your mounting backplate on the A64 boards. Ummm, I don't know about you, but I don't feel like pulling my PCI/AGP cards our, ram, etc, removing the mobo, getting the backplate off (which is glued on) and putting a new one it....Zalman is a bunch of idiots for not making it easier for A64 people.
3.) cost. First, the Zalman 7700CU is $40-$50...my XP90- $35+$1 for a fan. Second: the XP-90 has a fer easy system for switching fans. I can just pop off one, put in another. Done. The Zalman? ohhh, no, you gotta get their specially made fan....and that is BS! I don't care how good their fan is, I don't want to have to jump through hoops just to get a new one!
4.) cooling advatage of the 7700 over the XP90 (or XP120) is VERY minmal. Not enough to compensate for the price difference. Mind you, the XP-120 is huge, and can't fit some mobos, but the XP-90 is even just as good.