I've been using a 92 and an 80 mm pair of SilenX fans for about a month now, and I'm pretty happy with them. I have the highest speed available in those sizes, so they should be about as loud as they come. The bearings are clearly better than those on the fan that comes on the Zalman CNPS8000 or the SilverStone ones. I beleive the Zalman and SilverStones use ball bearings, and you hear a buzzing noise from these. The SilenX an other expensive fans often come with something like self-stabilised-oil-pressure bearings, which are much quieter and should last 3x as long,
Do your SilenX fans look like the ones from the Anand articles? Mine do, but I was under the impression that they are a new line. I believe others are complaining about a previous model, which was basically a re-branded part from another manufacturer. The claims from SilenX about CFM/dB are not accurate. There is no way the fans are actually that quiet, or you wouldn't be able to hear them even if your ear was only inches away. However, I do think that they push a reasonable amount of air (Anand's data agrees), and they are very quiet (again, Anand's data agrees).
I think that you could probably get nearly as good as performance by pairing a cheap Yate Loon with a FanMate (together those are half the price of a SilenX fan). Anyway, when buying such expensive fans as SilenX or Noctua (my fav), make sure you shop around. Apparently these things are cheaper in Canada. I've found good prices for SilenX at Bigfoot and DirectCanada, and good pricing on Noctua at DirectCanada. Bummer that Noctua isn't selling a 92mm fan. I know they make one because they've mounted it to one of their CPU HSF products, but they only offer 80 and 120mm fan sizes separately.