I had the opportunity to handle an Eotech XPS2.0. When I put this Sights down on the table.....look through the glass, and move my head to the left and right....the reticle moves with me. If the point of aim shifts as my position shift, but the sight does not move...doesn't this make the the sight pretty much....useless? Please explain my observations and how to counteract this. I mean...If my head was always in the same position relative to the sight...ie good check weld on the stock etc...I don't see this as being a problem...but if I shift my firearm around tracking a target etc.....my eye would not be in the same position and poa and poi would not be the same....right? what's going on?