Of all the streaming services out there, Google All Access has one major differentiator - it's the only one that lets you upload your own music to the cloud and then search/stream it in the same interface as the subscription tracks. Very handy for all those live tracks, out of print and obscure albums, et al that aren't part of the streaming library.
Spotify lets you sync local tracks to playlists, but they're loaded onto your device, not the cloud, so you're dealing with both storage issues, and device issues.