The ACOG is also magnified, whereas the EOTech and Aimpoint aren’t (unless you get the $500 3x magnifier).
My TA31RCO-A4 is mounted on my 20 inch model AR-15. I have the EOTech 552 XR308 on my AR-10 rifle. Sprang for the EOTech 4x magnifier for that one as well. My M-4gery sports the Aimpoint M2, with the 3x available when I need it.
The ACOG is my favorite, but I need to get a Docter red dot to mount on top for closer in shots.
Pretty much can’t go wrong with any of them. Expensive? Yes. But I wouldn’t trust my life with any of the cheaper stuff.
There are 100 buck magnifiers you can get. I can’t see paying 500 bucks for a magnifier that just magnifies, with no reticle etc to worry about.