I have a laser on my lc9 and bought one for my FN, I'm going to mount it on my HD shotgun. Because it will most likely be dark if I am sweeping the house with it. I got some advice from an LEO that it would be a good idea once the adrenalin is flowing. In broad daylight, I just can't pick that laser up as fast as I can pick up a target with my sights.
Just like you can't pick up your sights as quick at night.