I just removed an Eotech XPS 2-0 from one of my ARs and put on an Aimpoint PRO. It's my first Aimpoint, and I'm a little disappointed that the documentation that came with the PRO appears to all be Aimpoint generic rather than specific to the PRO. One of the things I'm curious about is, why does it come with a transparent rear cap, but an opaque front cap? Do you bother opening the rear, or just the front when using the rifle? I've got an LMT BUIS mounted behind the PRO. I assume I can use the dot either while looking through the LMT or while looking over it (in which case the dot will appear in the upper 1/3 of the tube).