1) Can't search within a playlist. Amazing that no one at spotify realizes this should be a requirement for all the mobile apps before any of them were released. Searching within a list is needed so if I decide I want to hear a specific song/artist that I know is in the list while listening to the list, I don't have to stop the list from playing just to play one or two specific songs, which would be the case if I use the regular global search.... now I'd be in the artist's songs area.
2) No library view. This is on the android version, but for some retrded reason, the geniuses at spotify have decided to remove it in the latest "beta" android app, and of course it's not in the ipad app either. A big reason this was a good thing to have is because it's the only view where you can search in (they call it "filter" in the app).
3) Can't scroll quickly in a big list. I have a playlist with about 1500 songs. It takes about 30-45 seconds of finger swiping to get to the bottom. There should be a slider icon to drag up/down to quickly get anywhere in the list, like the android app has when a list has a large amount of songs.
4) Can't perform add/share/etc functions on an album or list. I have a "songs to check out" playlist that I add songs/albums to when I hear something about them that gets my interest. Today my buddy told me about an artist that he likes. I searched for the artist, and would have liked to have been able to do a long press on their "greatest hits" album, and get the option to add it to my "songs to check out" list. Instead I had to do it for each song individually. So lame.