Yeah, I have a couple of MD recorders around that I use for listening on the go (running, cycling, etc). I find MDLP to be pretty good for playback when you're outside like that. With all the other noise around I really can't tell the difference.
Now when making a master, I agree you should use the best that's available, but that brings up a good point. What's worse, a show recorded in better quality SP that cuts in mid-song when you had to flip, or a slightly lesser quality complete uninterrupted recording?
Tough call. I think valid arguements can be made either way.
Anyway, I think MD is a fine walkman format, just not the best recorder (but far from the worst).