I no longer have a firearm with a laser, but man it came in handy learning the difference between aiming and holding a revolver (SP101 w/ Crimson Trace) and a semiauto. I was mortified when I saw just how far off my aim was at just 5 yards with a snub nose. I keep a flashlight by the bedside with a revolver, and a shotgun in the closet. The shotgun has a night sight. I will know the intruder by whether he is terrified by my Mastiff barking like Hell or if he is rubbing his face wrinkles and talking in a cutesy voice.
I am slightly ashamed to admit my AK has a flashlight mount though.
I'm not 100% on a laser for my use either. However, in reference to you saying leave lights on, what about a power outage, whether caused by a BG or other circumstances? Food for thought.