I've been messing around with this. Have a set of MBUS Pros and a PRO with a lower-1/3 riser. I really like how the aperture cleans up the dot for me. With the lower-1/3 setup, I have the option to go both eyes open for speed and tolerate a fuzzier dot, or drop down to cowitness and clean up the dot for greater precision when there's more time. I also like the option to fold the sights and just get them out of the view. Aperture rear also addresses the issues I have with typical notch-and-post sights on a long gun.

If setting up an LPVO with BUIS, the same symbiotic relationship between the systems isn't happening. My thought is that the optimal BUIS would be offset, so I could switch to them immediately, rather than having to detach the LPVO mount to get it out of the way before switching. Have I successfully reasoned myself to a "no duh" moment that's why the world is the way it is? Anything else I'm failing to think about?