I've been using a Sharp MD for a year past now, and while it has advantages, I'm not sure that overall it is better than the Aiwa JX849 cassette recorder that I used previously.
The automatic recording level of the cassette recorder is excellent and the 4 or 8 second repeat play feature is indispensible when transcribing songs
Just what you intend to do with the recordings is a major factor. For compiling listening collections the MD would be hard to beat. For foolproof instant recording I'm still not quite sold on the MD