Mr. Lappos, I believe the issue with the NOTAR concept has never been one of efficiency, rather one of SAFETY.
The design was spurred in response to the NOE manouvering which several times puts the tail rotor in the trees and tail rotor vulnerability to light arms fire.
The Sikorsky "proprietary" fan-in-fin design was to be a supposedly more efficient answer (still not as efficient as a conventional TR in terms of absorbed power).
Where are the compromises in term of costs to adapt it to the S-76 airframe and effective performance gains?