The larger red dot optics seem to be easier for me to pick up the dot. Larger the screen or tube the further from center you can be and still see it. Really like the circle/dot optics Sightmark, Holosun, and Eotech offer.
I was wondering about that. ACOGs are the definition of bomb proof, my buddy has a pic of an ACOG that survived an IED blast that even killed the rifle. Hard to believe any optic can take that amount of abuse and still work.