I actually had a guy with a trail 2 XP50 at my place yesterday, he was concerned about the image quality more than anything else. I showed him my GSCI 675 and his words were "that's more like optical".
The GSCI have a different thermal image to anything else on the market. They create a beautiful natural looking image is the only way I can describe it, they also shoot like glass. I've never had a more accurate thermal scope on the bench than my GSCI scopes.
The other thing I love is that the screen brightness is significantly less than other scopes on the market, makes it much easier on the eye for longer periods of time in the field.