I work for Google, so I know I'm totally biased here, but Play Music is pretty great, and it does recommend good new music to me, but the playlists by activity, mood, setting, genre of Songaza already look much better.
I can't wait till there's some integration and I can save Songaza playlists to my library and pin them to my phone.
Also, since Google Now began stalking my search habits, I get all kinds of useful recommendations about when artists I like release new material.
The acquisition of Songza will likely make a great product even better.
The recommendations are really great, though.
I was getting quite antsy with the lack of music related features. Google Music was feeling so.. lacking. I was close to switching back to Spotify, or trying something new.
Glad to see something is still being worked on heh
Is play music more established than songza? I think yes, and google is unlikely to maintain both of them in parallel.