For the same money, you could buy a Mitsubishi Solitaire and go faster with
a larger cabin and (probably) more reliable systems

How much faster are we talking here? Never flown in an MU-2, but I've
heard they can be a handful and there are plenty of NTSB reports on
Mitsu accidents. I read recently about the FAA looking into the recent
accidents with these planes. May very well be related to training
issues but the plane seems to have a rep, kinda like the Aerostar did
years back IIRC. I think I'd feel more comfortable with a conventional
aileron/flap than the spoiler. As far as systems reliability, not sure
why you think there'd be an appreciable difference(?)

Wooly