I probably am in the major minority here but at night, I do not want any light attached to me or my pistol. Especially in my home. I know my house, where things are where it is backlit by windows and where it is dark as the pit. I dont want any light giving away where I am. Especially not one attached to something, like my weapon that i need to be holding in front of my body
That is probably the biggest draw back of a laser. A rectile or some type of night sight doesn't have this draw-back. Unfortunately rectiles are too bulky for a CCW. They also don't offer some of the benefits that a laser has in close quarters battle, such as aiming when shooting from the hip.
Of course with my LCP I don't plan on activating the laser until I have acquired the target. Although mine doesn't have an on/off switch, it's easy enough for me to draw and get the gun pointed at a target without activating the laser. I do practice this.
In the "Concealed Carry Handguns 2013" magazine there is an article on lasers. The author, Caleb Goodings, says lasers enable people to aim more quickly. I find that to be the case with me. He says he also found that lasers made him more accurate at 25 yards. I don't normally shoot my LCP at that distance, but I'm sure that would be the case based on what I've found at shorter distances.