It was Roland's first effort at making a groovebox. Early versions had fussy midi clocking and filters were not a big thing to put much R+D work into at the time. It's sucessor, the MC505, was a little better but not much. I've seen them for cheap on Ebay too, but you'd be better off with something like the Korg Electribe EM-1.
I used to have a Boss Dr. Groove, and I loved that thing, it has so much editing and filtering capabilities. Are the Electribes even better than the Boss unit?