I can comment on that since i first transfered my whole cd collection to atrac3plus 256. For some reasons, there have been some scrissshhh (1-2 seconds and loud enough for me to be scared each time) when playing some tracks and on quite every atrac. No such thing appeared on rare mp3 i have. So that i initialized my HD5 device and reencode my cd to mp3 with CDex using lame 3.97 at 320 cbr, stereo. All I can say is that the sound is deeper in the low frequencies, clearer in the mids and less harsh in the highs. My headphones are the shure e2c. No way to go back to atrac.