I haven't played with a laser on a handgun, but after I mounted a weapon light on my AR-15, I thought about adding a laser too .
More as an exercise than something I needed, I used to play around with building hand-held lasers.
First things first. A >5mW laser is visible as ambient light diminishes, and green is probably 6 or 7 times more visible than red, but a 200mW - 650mW, 650nM (red), handheld laser is visible ANY TIME, and at greater distances than I'd think to shoot at.
I'd played with a mere 30mW, 532nM (green), laser was also perfectly visible in broad daylight too, at night you can see the beam the whole way, (several hundred yards).
The problem was the responsibility of shining a laser around that was quite capable of blinding someone in WAY under 1 second of exposure, (reflections aren't much better). Most shop-made / hobbyist lasers cause damage through the infra-red spectrum and don't invoke a blink reflex.
These hand-held lasers posed a credible hazard just laying around the shop, requiring protective goggles. Anyone picking it up doesn't realize they are holding something much more dangerous than a loaded gun because they don't know how powerful it really is.
Anyway, I think a laser sight is a great CQB low-light sight.
If I had a tactical laser mounted on a weapon, the only intimidation would be to the rest of the group of BGs witnessing how well the sight worked on the first guy.
YMMV