As much as I love adding extra weight to my rifle, I just can't decide whether or not it's really worth it to utilize an optical sight as well as BUIS. While I have little experience with the AR platform compared to most of you gentlemen, I understand the concept of "ounces are pounds, pounds are a pain." If you already have a reliable optical sight, is it really necessary to have a pair of irons on the gun as well, and vice versa? I get that people wanna be prepared in case the battery runs out or there's some sort of technical malfunction, but that can't be common at all! I personally would prefer having one designated aiming device instead of two. It saves weight and money, I can train twice as hard with it, and in my humble opinion the rifle looks more streamlined and sophisticated. I'm sure co-witnessing or some form of it is quite common among you guys. Can someone please explain to me why it's so popular? Thank you.