Bad design: playlist should be a side pane instead of a popup bubble
Parole has a playlist feature, but it's painful to use because it's hidden behind a button that shows it as a popover bubble. This means that you can't have the playlist on the screen while doing other things with Parole, like clicking pause or skipping around to different positions in the current playing song. It also means that annoying stuff happens, for example, if you try to click on pause while the playlist is showing, the playback doesn't pause and instead all that happens is that the playlist disappears from view. So you have to click pause again annoyingly. And then you have to click on the playlist button yet again to be able to see the playlist again.
It isn't really very nice to use if you actually use playlists at all.