I had an acog for a while, military take-off... It was fun for a while, but I always found it limiting me to specified uses. (target too far/close for 3x)
The eotech has always seemed pretty equal to the aimpoints, but I've had iffy quality control with some of the lower priced eotechs, ie - fuzzy reticles.
I'm really digging the new leupold line of ar specific optics, and while I'd love to drop a couple grand on a Miculek Vortex, I'm probably going the Leupold VX-R route this go round. Nikon's Monarch (M-223) series have also been outstanding for price point too.
Ive used Eotechs, Aimpoints and irons. Looked through but not shot with ACOGs.
I liked all of them, and they served their purpose well. For short range work its hard to beat an Aimpoint H1/T1.
Light and tough as nails, but maybe not as forgiving as the Eotech in terms of field of view. The ACOGS had great glass, but the eye relief was an issue for me. I really wanted something as tough as an ACOG, with a more forgiving eye relief, better field of view, and could switch between 1x and 4x without having to change my sight plane. Ended up with an Elcan Specter DR 1-4 and have been exceptionally pleased with its performance. Of course the buis that come with it are hideous, so i keep a set of Troy flip ups as well.
It really depends on what you're doing with it. For a general purpose/2A purpose AR, I like a high quality variable power scope with 1x on the low end. If you're using it for home defense or close quarters, definitely an Aimpoimt.
I have ran the Aimpoint, and the ACOG. Like them both a lot. But now I want to try something new. I want to try the Leopold Mark 8 cqbss 1-8x scope. The scope is a bad boy, but you do pay for it. So it may be a year or 2 down the road. From what I read at the 1x, its just like a Aimpoint. The one I want is about 3700.00 nib. I have seen used ones like new for under 3k.
I am going to get the Leopold VX-R 1.25-4X for time being. Just something to use for time being tell I get to that point.
Now if I only could get one listed, Acog all the way....