Linux music players: compilations and watching folders

Most music players have similar features, but there are two things that I find indispensable:

  1. watching folders for new files, ideally as a per-folder setting so it doesn't always rescan everything on startup.
  2. dealing with compilations and automatically grouping them as "Various Artists" or "Compilations" in a "browse by artist" listing, rather than filling it with single-track artists.

These are the main contenders:

In summary, only iTunes and Amarok can handle compilations well, but hopefully the others are not too far behind - particularly Songbird.