1. It's pretty awesome. The software works beautifully, quality on the free side is acceptable and the music catalog is pretty darned complete. Tempting to pay up for the premium sub.
2. If you want to just kick back and listen to music though, you need to have built some playlists. One of the biggest things I like about Pandora is missing - "just play music I like."
3. Cheap, for what you get. If you want music on your mobile device it's especially cheap when compared to buying the music.