I don't like how Spotify sorts out my library, especially on my android phone. I just get a long list of songs with no way of sorting. Sure I can do a search for an artist, but then what's the point of your library. They're queue system is stupid compared to Rdio's. The user has no control over it. On Rdio, you can add as many songs/albums into your queue for future listening and rearrange them however you like. It's all cloud-based so I can listen then rearrange on rdio's site using Chrome, then listen to it on my phone. With Spotify your only option is to use the app. If you want to listen to music on a friend's computer, youre gonna have to bring that app with you. Also the social elements and music discovery options on Rdio are far more superior than that of Spotify.
On Rdio, I can click on an artist/song/album and see the 50 most recent listeners. I can then check out their profile, see they're recent activity, what they've added to their collection (like Spotify's library but better) and see pretty much their whole history. If I like what I see I can then follow them (similar to twitter I hear, don't know i dont use twitter) and on my homepage, I get a page full of music that people I'm following are into at the moment. You can also write reviews for a song, artist or album, which usually just turns out to be a place for people to comment. Unless you have friends that have both Facebook and Spotify, Spotify's main source of music discovery without help from a third party will be through the "Top Lists" which is useless for me. Spotify also lacks an artist radio station, at least the US version which is helpful in music discovery.
One of the downsides to Rdio is the sound quality. It isn't up to par with Mog and Spotify. It's not entirely noticeable with every single song I listen to, but it is noticeable. The size of they're music library also isn't near that of Spotify. In fact, they have the smallest library out of all major US music subscription services. Spotify's app is also a lot faster than Rdio's. Songs play quicker. There's less load time. You can skip through parts of the song with little to no lag. Also, the ability to add songs from your iTunes libary into Spotify is a huge plus for me. This way there aren't any holes in my library and I can stop using iTunes entirely.
I really want to like just one service. I think for now I will continue to support Rdio. They are a smaller company and I like where they are headed. They are always trying to expand their music library and they do listen to their customers. They're android/iOS apps are better than Spotify's. They really just need to stay up to par in the sound quality department with Mog and Spotify and update their desktop client.
