I loved my minidisc players too. We had a portable one and a unit hooked up to our stereo. We got rid of all our old cassettes once we transferred them over to minidisc. Heaps better. That's why I couldn't understand why they never took the place of tapes. MP3 is what killed the minidisc, but I never thought Sony marketed the well either. I think they really dropped the ball with that one.
Once I got my first iPod touch, we just had no use for them any more so we shipped it off to Vinnes.
Incidentally, when I was on radio, minidisc was the preferred method for recording and playing sponsorship announcements. I guess that's all MP3 now too.
I loved mine too. I had a hifi with three (or five?) MD slots. It was AMAZING!
And I had a portable recorder model, which only died last year. My wife's player-only model still works, and one day I must transfer some of my MDs to my computer, before they are all lost forever :(