I'm running my own comparisons against mp3 vs. ogg vs. aac. MP3 recorded w/ LAME 3.96, ogg with the latest vorbis tools, and the aac with iTunes. CD tracks were ripped with CDex directly to wav for a sourcefile. Ogg quality = 6 (about 192kbps) MP3 = 192 kbps w/ HQ algorithm AAC = 192 kbps, stereo All EQ's set flat, listening with Grado SR60 headphones straight from my soundcard. So far I can only tell that mp3 seems to lose a bit of treble information vs. the rest. AAC and Ogg seem to be very similar at this point. Update to come later.