SharkSandwich - are you sure?
Excellent? Have you ever flown one? Just about the most complicated system of trim compensation via removable weights I have ever seen. Maybe that has changed now.
A classic example of a design idea leading to a truly complicated solution. At Farnborough the prototype used nearly the entire runway to take off - in front of thousands of potential buyers! Why are there not many ducted fan designs in use? They are not very efficient. Servicing the engine is not exactly easy - buried inside the ducted fan shroud. Even with the bigger engine Old Sarum airfield seemed rather short two up and no other payload.
Ask Derek Piggott about flying the Optica. I think he called it the Flying Lightbulb.