Bart, these points tend to be true for most other sights, especially dots that are not occluded. People get over them with training. I know of a situations in the 70s with KCMO Reponse Unit where a marksman with a borrowed AR-15 wounded a BG instead of killing him because the gun wasn't sighted in right.
Another important innovation has been the Bindon Aiming Concept. That's how all the ACOGs with the external light gatherer's work, and I do the same even with a cheap illuminated riflescope. Bascially, if you have something over 3-4x magnification, and a sufficiently illuminated graticule, then when you go both-eyes open, the picture thru the optic occludes and the scene thru the left eye becomes dominant, with the aiming picture from the right eye superimposed. So, an OEG, with all its quickness. Close an eye and you are back to magnified precision.
While OEGs and aimpoints are (more or less) parallax free, an occluded ACOG is not. Never heard a complaint though. Just keep a consistent cheekweld and it will all go okay.
Armson OEGs are used in places where they make sense now mostly. Sorta like the paintball example, I have seen them on grenade launchers. Dial in a range, which angles the sight and when you line the dot onto the target, the gun is correctly elevated. For a grenade launcher, the elevation is so high the barrel blocks the sight picture. For an OEG, that doesn't matter though.
Shoobe, I thought I was replying to you and snipped parts of your post I agreed with. To my shame, I had actually edited your post. Please accept my apologies. There was nothing offensive or wrong with your post, I just screwed up - BR