I have flown several systems like this, the RAH-66 Comanche had one (albeit a vastly different technology). It will be a boon to pilots in many ways.
AnFI, there really is no such thing as Vx for a helicopter. There are families of angles available, depending on the speed you chose to get to, and there is a distance needed to accelerate to that speed, which changes the resultant achieved angle. This entire complex thing is simplified by providing one speed, one angle and one solution known to work.
With the advent of a real 360 airspeed system, it would be possible to show a graphic presentation of the many families of procedures available to the pilot, so an appropriate one could be selected.
Better yet, we could just provide the power to be a helicopter, go straight up and make it simple again!