I've found another problem with Virtual Device and "create a sub-folder for each playlist": with "delete tracks that are not on the auto-sync list" checked, nothing is deleted. I'm currently syncing three playlists, and most of the files have ended up with multiple duplicates from reordering or adding tracks, which changes their position in the playlist and therefore the file name. Even if I uncheck an entire playlist, no files are deleted from the destination folder.