Terrible experience.
Without warning or notification, installation of Music App took ownership of my local playlists.
Automatically caused iTunes to no longer allow me to even view/access any music.
Installed Apple Sync and this app completely made a mess of all playlists automatically moving stuff around and creating copies of original playlists with partial content and inaccurate of what was originally created.
Installed Apple TV, those playlists only partially available.
Restarted computer, opened and closed all apps, re-created playlists and playlist groups.
On a small 500 song playlist Apple Sync works.
I have however 16,000 songs and every time I attempt to sync all Apple Sync shuts down somewhere along the process. iPad thinks all files are present and only 20% to 30% actually there. Re-start Sync shuts down again and some other songs show up while others are removed still in the same percentage of success.
Scared to have to rebuild all my music library researching how to go back to iTunes... at least it had an 80% sync completion.