I used it since day one, I really wanted it to stick, but it drained my battery drastically, even though I had my music cached locally and another deal breaker was constant restrictions bug that disabled explicit content every single day. I had to to go restrictions settings every morning to turn explicit content on, even though restrictions were off to begin with.
I thought everything was going to be fixed within few months so I kept using it, but after 6-7 months nothing has changed. I submitted bug reports and feedback to Apple a long time ago, I guess that didn't help. I thought that I could later join AM when the bugs were fixed, but then I read that they keep AM playlists only for three months. So I'd have to start again from scratch. Well, hello again, Spotify.