Hi Bob--good to see you!
That is helpful information! I had spent many an hour on the forums trying to determine how everyone was addressing/solving this, now many versions into Moodle 2. I thought maybe the "magic" was the alias files and I just wasn't using it correctly.
It seems to me (and I'd love to hear from others if I am misinterpreting) that most institutions are either using file storage external to Moodle, like you are with Google Apps for Ed, or are still relying on legacy files/"1.9 way" of file handling. Seems as though the latter doesn't solve the problem of seamless updates to derivative courses, but is at least a familiar way of dealing with files.