I use red dots, Eotech laser diffraction sights, and 1-4x low powered variable optics on my ARs and AKs.
Folks with astigmatism might need to use prism sights, which have engraved reticles, in lieu of dots or Eotechs due to possible optical blooming.
My own astigmatism still allows me the use of them when wearing glasses.
Everything depends on your intended use for the rifle, but IMO, a good quality true 1-4x, 1-6x, or 1-8x low powered variable optic with a true daylight bright center dot offers the most versatility.
For “fastest” target acquisition at close range I’d recommend an Eotech.
For “fast” acquisition at close range with extraordinary battery life I believe it’s offered by the red dot.
For “reasonably fast” acquisition and the most versatility, I believe a true 1-xx LPVO with true daylight bright center dot illumination offers the best solution by extending the range at which you can accurately identify and shoot at your intended target.
For red dots I run SIG Romeo 5s and they’ve been great, but I won’t buy anymore Chinese optics ever.
For low power variable optics I run a couple of Steiner P4xi and they’re outstanding.