I have been looking at all of the various options formusic servers over the past few months. I had a specific set of requirements, some of which were set in stone, while others were 'nice to have' Examples of the former were 1) the ability to output 24/192 or 24/176.6 WAV files, 2) AES/EBU outputs, 3) best possible sound card, and 4) full automatic backup. The desirables included touch screen control (as implemented by Sooloos or Qsonix), and comparatively easy implementation.
I have just arranged to purchase a Music Vault Diamond, which satisfies all of the criteria with the exception of the touch screen. Sound card in the Diamond is a Lynx AES16. Control is handled by a supplied netbook running either Media Monkey or iTunes. Price at list is less than 1/2 that of a Sooloos. The Diamond will feed my existing Berkeley Audio Alpha. Should be interesting!
Will report back when I have some experience with it.