RE: burris
OK, that is the FastFire that is similar to the old Optima and the newer Trijicon and Doctor sights. Pluses with the Burris is that the frame is metal instead of plastic and the lens is glass instead of plastic. Adds a tad more weight but a lot more durability. And it won't have the problem with gun solvents etching the lens. I found that out the hard way.
I would put it on a shotgun before an Eotech, just because of the mass and clutter. Burris makes good stuff and not as pricey as an Eotech. Plus it could go on another gun at some other time more easily than the Eotech.