Tacks,
The whole thing really didn't really work out nicely, the helicopter had rotor instabilities at high speed that caused at least one crew to be lost during development. It was scrapped because these problems were never really solved.
The rotor used a unique control system that worked with a stabilizer bar type system, where picth changes were fed thru the gyro bar and then to the blade.
The payload was actually fairly small for its installed power, the wings caused a loss of hover performance (about 10% penalty for the vertical drag of the wing) and the tail thruster was a weight penalty as well.