I'm pleased with the -j option to specify a playlist, but something seems to be missing. The parameters to -j expect a song number, but there doesn't appear to be a way to find out the song number for a track I've just uploaded (short of doing a -l and grepping for the song name). The newly-uploaded track won't necessarily be appended to the end of the list; if some songs have been deleted from the rio recently, it may get dropped somewhere in the middle. (While we're at it, it seems like there should be an option for deleting all the songs currently on the rio, something like -d "*", without having to reformat the memory card.)
This makes it difficult or impossible to write a script that will upload a series of tracks and then reliably create a playlist of those tracks. In fact, it seems to be difficult to use the playlist feature at all, other than to make playlists rather painfully by hand.
Even in the API, there doesn't appear to be a way to find out the song number that your track was/will be uploaded to, so I can't even write a C program that will upload a complete playlist for me.
Am I missing something?