Motion Scaner may be more useful where results of scan will be displayed on map to end of turn or to real check by user units... Marker on map should be somehow symbolic but like on Motion Scaner we can identify size of detected objects.
For me preferable will be some floating/animated objects with graphical size of normal units.
Additionally maybe w add alien version of this technology but with better range (or add this as second option to Mind Probe) or detection rating.