@Jeffro - Interesting that you mention MP3s. I've primarily used it for storing documents and images.

I did do one theme, however, that required a portfolio section. A custom solution was put in place to manage the portfolio items themselves, while using the Media Library to store Flash Video (FLV) files as well as MP3s. These were then loaded on the frontend into a custom player.

The Media Library handled the above pretty well. Each file was a few MB in size and the uploader worked like a charm. :)

Will have to get down to writing that blog post soon. :)