I just bought a "Nexus PHT 3600 Skive Tech Silent Pentium 4 Heat Sink & Fan" and it's not silent. In fact, it's not every very quiet. If I'd noticed that it uses a 70mm fan before I bought it, I might have been a bit more sceptical, but I'd read good things about Nexus fans and bought this thinking that all their products would be just as good.
I've got a Zalman F2 92mm (PS92252H) which is running at 7v to cool my P3 600Mhz Katmai, which I believe has specs at 7v of 1600RPM, 17cfm and 22.6dBA, and the Nexus HSF at 12v is definitely louder than that, so it can't only be generating 19 dBA like the specs claim
I can make it acceptable by running it at 7v, but I could probably have done that with the HSF that came with the PC (Coolermaster fan). In fact, if I find this is the case and the temperatures are acceptable, I'll be demanding a refund from the supplier (including the return postage. Why should I be Â£3 out of pocket with nothing to show for it?)
On a more positive note, the Nexus 80mm fans I bought are very quiet, so I might replace the 92mm Zalman with one of those, as they appear to be much better (Nexus 22cfm 19dBA @12v vs Zalman 17cfm 22.6dBA @7v). However, whilst I got the Nexus stats from here, the Zalman's stats come from http://www.pcpro.co.uk/custompc/labs/92627/zalman.html
so they might not be accurate/comparable (in their tests, they found the Nexus 80mm produced 13cfm @26.4dBA!). Is there anywhere here that has results for these two fans under the same test conditions?