[kall]

I don't think it's fair to say that it only works for simple library situations. I happily tend to a large and intricate library with it.

You just need to give up on real files and folders. If you want the fusion of library focus and streaming service, they don't make sense anyway. iTunes is going to take over all management of the filesystem. You just have to surrender all that, than it can be very powerful.

If you actually wanted to migrate, you could copy the filename into the comment tag on the way in, but that seems dirty.