One thing that I don't understand is why most music programs do tagging in the same thread. That is, if you change the genre of a CD, your player is blocked (you cannot press any other keys, change music, etc) till the progress bar finishes.
The only programs that do the right thing (multiple threads) are Mediamonkey, foobar (if a bit cumbersome), and Jriver.
Winamp lets you enjoy the full progress bar.
Another thing that bothers me is that folder monitoring (i.e., auto-add files to library when I move them to my music folder) plain sucks. Winamp doesn't refresh immediately. Same for ratings: and there's no easy way to do a manual refresh.