There are a few comments comparing Minidiscs to CDs, I think that's the wrong way to look at the format. My mental model for Minidiscs is much more similar to

There are a few comments comparing Minidiscs to CDs, I think that's the wrong way to look at the format. My mental model for Minidiscs is much more similar to tape, it was so easy to use them to record. As a teenager this was the most exciting thing about them -- you could record ~CD quality audio from CDs (I had so many MD mixtapes!) or the radio. On top of that, you could make your copy feel polished by adding track markers and names, giving you information about the track playing when listening and letting you skip back and forth between songs. This was a huge upgrade from cassettes and an upgrade from CDs because you didn't need to go through the rigamarole of burning. Of course, this doesn't even touch upon industrial design of the units which has already been well covered in this thread. If you'd like to browse through some old units and get a sense of that, I recommend minidisc.org.