Just bumping this because I think it's very interesting and useful. I've done 128kbps vs 320kbps tests in the past before and save for some very minor things (more distortion on clear high notes with lower kbps files for example), I can't reliably tell a difference. As I have always felt, recording quality is what it's all about, not bitrate. Granted, I am a music listener and not really an audiophile. I am sure certain listeners have their ways of finding out structural differences between bitrates though.