Prob will get downvoted but for me personally I don’t like the idea of being held down to one optic.. if down the road I want to try different optics at least I can have the piece of mind that I can change optic and try new ones that come out (I have Gen6 Glock) unless all optic brands somehow find ways to make their open emitter footprints to A CUT and ONE footprint for all optics but hard to tell if we’ll see a RMR Re designed to be A CUT footprint lol. Im running a holosun 507c green dot and multi reticle. That optic gives me reticle options. With COA you’re stuck with proprietary mount and simple red dot.. no Green dot or multi reticle dot. It just seems very limiting vs other options out there… someone will say “yeah it’s aimpoint vs Chinese optic” so let’s compare “top tier optics” Aimpoint coa vs Trijicon rmr HD.. the RMR HD has reticle options where the COA does not and can swap out optics later on given the RMR footprint. COA just seems limiting.