With the latest release of Spotify for Desktop (12 Mar 2015) we've seen a lot of functionality removed from the client.
- Search in playlists.
- Support for editing meta data for local files.
- Support for adding local files to spotify from finder.
- playlist dividers/separators in left sidebar are no longer working.
- Viewing a folder with subfolders now shows a list of folders instead of all songs contained in those folders.
- No longer possible to resize columns in playlists.
- No longer possible to re-arrange columns in playlists.
- Way to much whitespace in playlists.
- Dragging a folder into spotify destroys the app.
- The app resets scroll position when changing playlist.
Apps have been completely removed from Spotify and will not be returning. Pressing "del" to remove a song from a playlist also no longer works. Just two features that are missing from this list.