I have Spotify premium. I use it everywhere - home, work, car. Love it - well worth the $$$.
- biggest pro: playlists are downloadable to mobile devices. That way if you are off your wifi, and on your data plan (4G) - you aren't eating up your data plan to stream music in the car.
- interface is great. crushes itunes.
- can import your current digital library and act as a single source media player for music
- streaming quality is adjustable
- works on everything - PC, tablets, phones. I have it four devices and never had a problem
- library doesn't always sort bands intuitively. For example you will find records by Reverend Horton Heat, and by The Reverend Horton Heat. They will be listed as different artists. That kind of thing happens all the time.
I can't think of many things I don't like about it. I ripped my CD collection, sold the entire lot of them, bought a Spotify subscription and never looked back.