go for the 003 if you are recording into ProTools. Input monitoring is tricky with the Profire, I never found a reasonable way to do punch recordings with the M-Audio box, as Protools does not have a "software monitoring off" function (unlike Logic), you have to dismiss the nice hardware monitoring of the Profire, or you'll hear a nasty phasey mix of hardware and softare monitoring upon engaging record (unless you want to hit the mute button all the time). Regarding sound quality I cannot say if there is a difference, but for me the Profire is a troublemaker in the studio and I wish to get rid of it as soon as I get some higher end converters.