I know the Aerostar is not an experimental but it is so good that I’ll do an exception..
Among the two engined piston powered aircrafts out there the aerostar is a absolute favourite. Why? There are a few things that I think puts it apart:

Looks! It gives the impression of a small, fast propliner even though it is actually physically smaller then any other manufacturers counterpart it is not even as big as the Aztec.

Speed! It is actually faster then most turboprops…

Design! The part count on this aircraft is usually quoted to be 50% less then any other.

Economical! Quite cheap to buy these deliver more speed then turboprops and even if the 100LL price is way higher in Europe then Jet fuel the $/mile is ridiculously low compared to most others.

I don’t really know why I am so fascinated by the 50% lower part count in this aircraft. Maybe it just that it is the final confirmation that everything is very much an aircraft where someone spent a lot of time thinking things through. Sadly enough when a larger company produces an aircraft it usually get an mixed up personality and in this case thanks to its one man design team it didn’t.
Ted smith the designer seems to have one main design goal and a second reflection. The first goal being SPEED, the second reflection more being something like “how are we going to obtain the speed but still keep production costs down?”
The production cost were mainly held low thanks to the low parts count so if you have a closer look at the aircraft you’ll see that the stabilizer and fin are almost identical. With identical shapes the parts are the same, hence lower part count..

It is a forty year old design originally being designed in 1963 but it is still alive and kicking. Even if, as most other designs, have passed through many owners during the years, active development is still in place. The current owner of the design Aerostar aircraft co. is testing a jet driven version, the Fj90 (jet engines could be retrofitted onto old aerostars to become Fj90) There is also a slightly altered eightseat Fj100 in the plans. Right now the project seems stranded because of lack of funding. It is a shame if it doesn’t happen and it would be a great idea since the airframe was already in the sixties tested to 800mph…

So what do I don’t like about the current piston aerostar? Well, it is a long concrete runway type of aircraft. Somewhere around 3000ft of hard runway is a minimum. But where am I gonna find a 260kt twin accepting my 1500ft grass… 

Specs Super 700

Wingspan 36ft 8in
Length 34ft 10in
Empty: 4600lbs
Gross: 6315lbs

Vne: 260kt
Cruise: 261kt
Stall: 81kt
Engine: Lycoming 540 290-250Hp depending on type.

Links:
Longer and good background story at pilotfriend
Aerostar aircraft Co