The earlier question about black rifles brought up some comments on optics, so I though I would ask what people like and are using.
I have variable power scopes on all of my hunting rifles, from low power models to high power, depending on purpose of the rifle. For my ACR, I started off with an aimpoint, believing in all of the hype. Also tried an Eotech as well. All was fine until I started wearing glasses. My vision is not bad but at distance I need a little correction to count the tines on a buck at more than 100 yards. I also hate to hunt while wearing glasses, they are worthless in the rain or mist. Anyways, with glasses on the red dots work fine for close (100 yrds or less) but grow less precise as the distance grows, as would be expected. Without glasses, the dot is distorted and not precise.
So my solution has been to move away from red dots and use variable power scopes (1-6x or 2-10/12x) that have diopter adjustment on them. Glasses on, diopter is set to zero, glasses off and it is a quarter turn to the right (or there-abouts). I do like scopes that have battery powered dots like a Leupy VX-6, but they are not cheap and the dot could be brighter in bright daylight. Also, if the battery dies or there are no batteries, the scope is still usable and not a paper weight like a red dot would be.