I use one one on my AR and like it very much for that application. For coyote hunting
with 69 gr SMK, zeroed at the cross hair, top of the first circle is 200 yards, center of the 3rd circle is 300 yards.
I have not used them at real long range so the crosshair thickness has not been a issue for me. The circles do give you many aim points to choose from in certain applications.