Playlists may not be entirely safe if you've upgraded to iOS 8.4 and iTunes 12. There's a few bugs around regarding iTunes Match/Apple Music, one of which is that it may trash your library/playlists.
Not suffered from anything quite that nasty myself, but none of the artwork from iTunes has made it onto the iPhone (but the iPad is OK). Not the end of the world, but annoying if you've been an bit anal and made sure that everything actually has artwork...
Biting the hand that feeds IT
