Rick - there's loads of info on the web - but its like wading through mud half the time. You could try http://www.minidisc.org.
The words 'minidisc' and 'comparison' yield quite a few hits on google.
Harmony Central have some stuff here

I'm really happy with my minidisc. It was pretty cheap and seems to do a good job. I've recorded some songs to send out to my sister in Japan & taken them from the minidisc onto tape - they sound pretty good for a home recording. For some reason the level going in from the minidisc to the tape recorder is very low though & you end up replaying the tape on a high volume setting (but no hiss or distortion so I suppose that's what a volume nob is for). The only thing I didn't like was that when I played back on my parent's hifi there was a noticeable slight loss of the undertones of my voice which was a bit bizarre (I thought it made me sound very saccharine - yeurkkk). I'm going to experiment a bit because I wonder whether I should have had the bass boost on when I played the minidisc into the tape machine (analogue leads connection). Sounded fine played back on my hifi, so it could be just because dad's equipt is about 20 years old.
Anyways - its a brilliant fun new toy!!!!

Kris