My only complaint (and mine's of the older clamshell variety) is that they stopped producing batteries for it and the thrid party one I got won't hold what the charging system considers 100%, so it gets charged all the time, and the new battery is wearing down pretty fast.

I've yet to find an mp3 player that I really like, but I don't really use it for that anyway. Otherwise, I've not got any complaints about the applications I can find for it. It's obviously slimmer pickin's than for Windows, but seldom am I unable to find something that doesn't work at least reasonably well for my purposes.