Just curious, but why do you want a laser? The only situation I can see it useful is if you must shoot from an awkward position where you cannot view the sights, but putting a laser on a target and finding that spot with your eyes takes longer than just using the sights. Some people say they're a deterrant but I think "gun pointed at chest" is enough of a deterrent as it is. At night I don't want a bright red 'shoot me here' dot on my weapon and they don't have the blinding effect that a bright tactical light would have at night, I'd rather just use my night sights and preserve my own night vision. In the day the dot can get washed out depending on the background, and certainly never looks the same on different targets/surfaces and different distances so it can be difficult for your eyes to pick out quickly, hence making it slower than just putting your sights on target.
But if there's any reasons to have it that I've overlooked, besides that it looks cool, maybe, some of the crimson trace grips look nice and they don't add bulk to the weapon so I can see adding them for the (rare) occasion one would have to shoot offhand or from the ground in a fight or around cover, somewhere you can't put your eyes on the sights.
