They're a useful tool. As others have mentioned they are more useful in a stress/panic, situation, where you may not be able to bring the sights up because either you don't have space, or time. If you see the laser on the BG you pull the trigger. Obviously for this reason, they aren't exactly useful at the range where you can use the iron sights or optics. Like they always say, it's better to have It and not need it than need it and not have it. The only real drawback to a laser sight, that I can see, is the added weight and equipment hanging from the gun. A positive way to look at it though, is that the increased weight will generally reduce recoil. I would carry a laser sight in my defense guns, if I had any that could mount them.