22clipper,
The old ABC demonstrator flew in the 1970's and early 80's and was the predecessor of the X2. Here is Dave's excellent site:
http://www.unicopter.com/0891.html
The X2 plan is to develop the airframe, the FBW controls and then the X2 rotor, so it is being flown that way. The first two steps have been accomplished, the third is approaching (the blades are going thru qualification, I think, and flight test is being planned).