Mike,
The props are quite inefficient ways to transmit power, typical prop efficiencies are less than 90%, small ones even worse.so the rotor loses are quite high here. A main transmission loses about 2 to 3%, and the tail rotor system is typically 3 to 6%, so if the two are compared, they don't quite break even, and you gave up yaw maneuverability in the deal.
On the other hand, Igor Benson is a genius, and a wonderful enthusiast. I met him once, and he was a really wonderful guy.