I started up a trial of Music Unlimited to utilized across my PC, Vita, PS3, Android phones and Galaxy Tab. I have a home server full of music that I stream to devices on my network but I was looking for a non-Apple, non-Google alternative to cloud music storage combined with a selection of current music I can listen to.
Music Unlimited on the Vita is interesting. You can select any collection of songs or albums and download them for "offline" listening. While you can't play a game and listen to a song streaming in Music Unlimited, you can listen to a downloaded offline song while playing a game on the Vita. Music Unlimited also downloads music while you're playing, so I've queued up a few albums, played some games and after a few minutes I have a whole album downloaded to listen to.
It's interesting, not sure if I'll subscribe but wanted to give some gaming-related feedback.