Quick pull and shoot from the hip or intimidation. Other than that I don't feel they are for me. I don't like the added complexity really. A little extra bulk, batteries, and something I have experience on 2 different sets of CT's now... They lose their accuracy after being fired and need readjusted. I don't prefer them under most circumstances.
That being said, I do like the laser/light combo on the rail of my G21 for home protection which I may also put on my KSG. I like it because if stalking my home it could be useful and takes up 0 more space than a light.
My US marshal buddy/trainer is vehemently opposed as he claims (as others have on this post) that they impede training with the dependence on something other than the front sight.
FINAL THOUGHT FOR CCW: kind of like switching from a 1911 to a Glock it would not be advantageous to go from sight shooting to laser shooting IMO. This could be a reality in the event of a damage to the laser, dead batteries, switch inadvertently off, picking up BG's gun or just using a different CCW from day to day. IMO IMO IMO