I left Spotify for Beats. ...
I had left Spotify for MOG and MOG was awesome. It had a better library, not as many lame covers and overall better digitized quality than Spotify.
Then Beats acquired MOG, for $15 million. Then Apple acquired Beats for 3 billion.
MOG had a great feature, named Artist Radio, which allowed you to create a radio station based on an artist, like Pandora. Both Spotify and Rhapsody have something similar, although neither has an algorithm as good as Pandora does. iTunes Radio's algorithm is not great, either.
So, Beats removed the Artist Radio feature from MOG, got rid of the desktop app and generally degraded the UI.
I hate Beats and rarely listen to it anymore, even though I have prepaid for a year.
Thinking of going either with Rhapsody or Spotify now.
I have also long abandoned my 200gb of lossless rips I still keep on an NAS. Streaming is so much easier and streaming Artist Radio, like Pandora, allows me to discover new music I might like. The sound quality with higher bitrate streams is close enough to lossless that I can't tell the difference on the same material. Yes, I do have an "audiophile" system with great speakers
P.S. I have been searching for a random sample of obscure artists in Beats, Spotify and Rhapsody and I have to admit that Beats still has the best library and the least amount of covers (some of which can be almost as bad as karaoke

.
This is not credit to Beats, however, but to MOG. Beats acquired the MOG library when they bought it.
By my totally unscientific and limited survey, Beats has the most complete, high quality library, Spotify is next and finally, Rhapsody. Rhapsody is closer to Spotify than Spotify is to Beats.