Depends on the purpose. For general use at the range or in the woods, a max magnification of 6x is more than enough especially with my 14.5” barrel.
Most folks I’ve seen with DMR-like builds in 5.56 run at least an 8x as it’s adequate for torso-sized targets up to 400-500 yards.
Yeah, I like having the AR as my DMR and then maybe putting an Eotech, HS510c or maybe keep the 3x prism on the AK.