I have been pondering maybe the same thing since the PM hunt in February. That is - replacing my Zeiss Conquest 3-9 on my AR .223 with something that I can shoot with both eyes open on the fast movers up close and also use to work up loads on the bench.
The ACOG is built to be extremely durable and is excellent, our military uses a bunch of them.
Another post inquired about the Trijicon Accupoint 1-4X24 - I have looked at two of them with red and green post. Very fast with both eyes open and huge field of field. Faster than the ACOG for me. While looking at one of these another customer that runs deer with dogs in the swamps told me that that scope was the best for that that he had ever tried. However I like the idea of the German reticle #4 for longer shots and bench work. I have not been able to lay hands on one of these - yet.
Larue has a package deal on them including mount.
Another scope that came to my attention is the Swarovski Z6I 1-6 X24. $$$$$! Unbelievable low light capability - they turned the store lights out - and 6X + larger field of view = both eyes open.
The down side of this one for me is the battery even though it is a common one. I would need to turn the light on when I started calling to match the speed of the Trijicon Accupoint, getting on the fast movers up close in the thicker areas which is all areas around here.
I have discussed the Trijicon Accupoint with another member here that has had the post reticle and now has the German #4 and likes it better for longer shots. This is the direction that I am leaning at this time.
Back in the day using peep sights on an M-14, 350 meters was easy and I hunted for years with a fixed 4X on a .270 and could get good groups on the bench. Higher power scopes on an AR .223 for me are just slowing me down on the close fast movers with their limited field of view. At the PM hunt this year I never took my scope off 3X while calling.
Longer shots, out to the limits of .223/ with energy left, don't bother me. It's the close fast shots that I want to set up to handle and large field of view with both eyes open is the key for me, and the Accupoint seems to do that best - personally.
Other types of hunting - that I don't do may require higher power scopes?
I have shot ARs with the ACOGs and that was what got me into ARs.