It seems to me that individuals, unable to find what they want from a reputable manufacturer, are experimenting with 'new ideas' on individual bases.
This suggests that the difficulty lies in the manufacturers' failing to provide what the market wants, (coupled with a little desire to muck about by owners of small aircraft).
Others feel the same way, perhaps.......?
Really, if someone wants to build a 'quiet' light aircraft, they MUST spend their time and efforts convincing regulators and manufacturers to MOVE WITH THE TIMES. Mucking about yourself to find a one-off answer, achieves nothing but the launch of a potentially unsound, untested, and deadly design.
When that design claims a life, the public will not have any interest in its genealogy. They will simply see another 'small aircraft has crashed' and all our reputations will have been damaged as a result.
Sorry, Genghis et al, but I don't believe that aircraft design and manufacture should, in 2002, be in the hands of wealthy individuals with big garages and time on their hands.