I use LAME myself and even though it says 'joint stereo' doesn't hurt imaging but help, don't know if I believe it. I personally don't use it to encode. Napster files are very widely inconsistent of quality. I find allot of them to be muddy sounding, mostly the files are overcranked so amping them of course only makes them worse, I fix them w/CoolEdit. CoolEdit takes the raw wav and you can tweak it and encode at YOUR favorite settings.
2p

#695 Mk2 BLUE 12Gig

Ask and I may tell you