That was one of my main reasons for switching to Rdio when it was out, and while I really liked Rdio for its UI, it definitely had enough bugs/delays in song starting that I ended up moving (reluctantly) back to Spotify until Apple Music was released. Now, with that handled along with cloud uploads of my local media (I buy a lot off of bandcamp), it feels like a much more whole offering. I wish social and discovery features were up to Spotify's levels, but I personally have moved away from those for various reasons anyway, so it's not as much of an issue for me as it is for users who really utilize those features.