The answer to the "how big" question is that it is CPU and memory dependent. On the Empeg/RioCar player, the new layout probably won't save many cycles unless there are a couple thousand tunes/playlists or more -- each tune/playlist results in two files in the fids directory.

Most of us have more than a couple thousand fids by now.

IT shouldn't make much/any difference on a stock player, but it helps when using the web interface, and frees up some CPU for third-party apps that may be active simultaneously with the music player.

EDIT: And of course it speeds up FTP and mirrordir quite a bit under some conditions, and should speed up database rebuilds by a measurable amount.

Cheers