I used my TA31F during my year long tour as an infantryman in Iraq. It allowed me to effortlessly engage and hit everything I wanted it to. The TA31F ACOG provided an advantage over other optics in several ways; the ACOG requires no batteries to function, it provides a fixed four power magnification great for enhancing target acquisition, it has a crisp and clear sight picture and the BAC chevron reticle system that automatically adjusts brightness to suit the back lighting and can be used with both eyes open for close ranges, and is incredibly durable. My M4 was dropped from the back of an MRAP and landed directly on the ACOG which put a dent in the fiber optic plastic, but didn't even effect the zero. Two of my personal rifles at home have these fantastic sights on them thanks to my positive experience with the sight while deployed.