They look gorgeous, and were sold as an owner-pilots aeroplane. So for an owner who wants to fly pressurised with just one or two up, and get noticed on the ramp, then I guess they were hard to beat. I flew them commercially for a few hours and never really liked them. They were slightly better than the A56TC but, in my opinion, not much.
A useful modification (but never applied) would have been to replace the high revving Lycomings with slow turning, geared, Continentals (think C404/421 engines). Of course to get the power the small props would need to be changed.....main gear legs lengthened and moved forward and nose wheel replaced with a tail wheel. Add a few extra pop rivets, certify it as aerobatic, and the Duke would be a winner
