In this post John looks specifically at the FlightScope X2's Angle of Attack.
"...I have been quite critical about the FlightScope machines and there ability to accurately measure the club delivery data. Specifically, there ability to measure the club heads Angle of Attack into the ball for an iron shot. This information is critical for accurately determining the clubs 3d path at impact.
So the big question is, did the X2 solve this issue? As far as I can see, the answer is YES."