are there standard ways of describing how good this sort of gadget is, e.g. in terms of the maximum velocity/acceleration and minimum size of objects it can track? And/or maybe in terms of some other parameters that don’t occur to me off the top of my head? 
(and yes, I understand that the main application of Kinect itself for now seems to be major “gestures”, so maybe accuracy is not all that great now)
Also, is Kinect inherently distinct from “3d scanner” or are these systems of the same principle but with different accuracies and price points?