as others have said, it is easier to hit targets farther away/shoot more accurately. That said I am much quicker with irons. Aquiring/reacquiring the dot is not as fast for me as irons but it is gradually getting better. i can be just as accurate with irons, but it requires more focus. I am fairly new to the red dot game though, only been seriously shooting with red dots for a few months. I've owned an unreliable handgun with a Burris fastfire 3 on it for about 3 years, but no serious use because of the feeding issues that handgun has. none of mine have failed. the glass cracked on my best friends fastfire 3 during normal shooting while I was there. it still was usable however. It appeared to be because brass was somehow hitting it during the ejection process. I have had iron sights fail, front sights flying off, sight screws coming out ect... the battery thing bothers me and always has, its not as much of an issue with the newer crazy long battery life ratings, solar charging, shake awake, tritium and fiber optic illumination ect, but eventually they always die, and tritium quits though it IS several years down the road. for those reasons i think for defensive use co witness iron sites with red dots are a good idea.