My one big gripe with Spotify is that they don't serve up a lot of the music I listen to (WARP-label), and it seems that all music before 2005 is either a karaoke or cover track – when I search.
I'd check again, they have a load of warp now. I also noticed all the Autechre albums are back on again. Things appear to be more like they were in the early days of spotify.
It's just too limiting, for me at least.