I see a couple problems with how the playlists are managed. As a person with 300 songs, I hate that I have to drag a single song for a very long time; up or down. This isn't too important, but it'd be nice to have. I also think mass-selecting songs should be an option. Choosing many(or all) songs in an album to add to a playlist, like, dislike, or in your own playlist, choosing a lot of songs to move. The third is adding an entire playlist(or album) to another playlist just to streamline things. These two are the ones I really recommend.