Obviously some of these people have never owned a t2 - Aimpoint Duty RDS 1x Reflex Red Dot Sight

Is there a ring when the brightness is up to a certain brightness? Yes. Is it the exact same as on a t2? Yes. For the rds, once you get the brightness up over half way and you're inside you will notice a red ring if the dot isn't positioned perfectly in the center of the window. It's the the same on a t2, but since the t2 has more brightness adjustments it happens at about setting 7 on the t2. If you're outside it's hardly noticable unless you're one that likes the brightness cranked to the max. The optic deserves 5 stars because you're getting aimpoint t2 reliability and durability for less than $500. I also like the push button adjustments. They could be a little more tactile for use with gloves, but it's not that big of a deal imo. The biggest pro (no pun intended) for this optic is the aimpoint durability and reliability for less than $500. That's a win, i don't care who you are.