Belkin G+ works with the new 2010 beta and gives excellent coverage (100% at home). At the moment I am using Belkin g adapters with 2009.4 KDE3.5 & LXDE and I am getting about 70% signal strength. I have had no problem setting up and running Belkin. I've not tried N series so can't comment on it.
THanks for the reply. Is that the F5D7050 or 7051 you're using? (from some searching, I think they use different drivers and/or firmware)