I have one of the Belkin PCI cards which has worked without any trouble in a Windows box for several months now. I haven't tried it in a Linux installation yet, because the OOTB drivers in Ubuntu and SuSE don't support WPA. I don't really want to use WEP - it seems a retrograde step. I'll wait.
As far as customer reviews are concerned, I'm very cynical about negative ones. They often say more about the reviewer than the product. Looking for a DVD rewriter to match my silver PC case, I found a customer review which marked the NEC ND-3540A down because although the front face was coloured silver, the tray inside wasn't - it was beige.
I bought the NEC. It matches the case fine. It works fine too. The interior is
beige. Who cares?