The quick answer:...
Minidisc recording at it's most basic level is supposed to be as much like old-school cassette recording as possible,... 'cept with more clarity to the sound (no hiss) and a whole lot of higher capablilies that only digital can offer.
Newer models of MD have been made as PC/'puter friendly as possible, with drag & drop loading of songs to MD.
The real advantage of MD recording is the concept of cheap removable media that's suitable for archival purposes. The functional advantage is in the convenience of quickly changing media when the disc is full,... (like it's predecessor the cassette tape),... as opposed to many more modern digital recorders that require a PC-dependent dump/backup scheme to archive data. (That's not usually too convenient in the middle of sessions or on remotes).
The other advantage of MD is it's size. It's small, & is a favorite format of legitimate concert-tapers and bootleggers alike. Anything that small is inherently more convenient than something larger. Minidisc is small. "Mini" is in the name.
Hi-MD is really the pinnacle of this technology, that now offers "straight" PCM (cd-wav format) recording. If you're considering MD recording this late in the game, I'd by far recommend getting Hi-MD. That's unless you really want a "console" style home deck, which then you'd be best with "original" MD,... as Hi-MD recordables are just the handheld format, not the home-deck style.
I have "original" MD recorders (home decks and walkman-type players), and I'm quite happy with them. They sound fine.