Some thougts from Germany...
My first DMR was a 16" German Made AR with folding ironsights and an old Hensoldt FERO Z24 4x24. This rig was an excellent rifle out to 600m. First round hits at 16x16" targets from "rucksackprone" in under 20 seconds were the norm. Start standing with backpack slung, signal, pack down, go prone, shoot.
Then my eyes got worden, I could no longer focus the reticle.
Sold the Z24, bought a used Swarovski 1,5-6x42 reticle 4. OUTSTANDING SCOPE! I can observe impacts in the dirt at 500m with it.
With a similar scope on my AR10 I shot at a driven hunt three boars at under 50m in under 10 seconds. So this setup works perfekt for me from 0-600.
My actual go AR15. Just completed, has to be shot properly in next weekend.