Higher power green is desirable so you can see the spot in daylight out doors.
Other than that they are a disadvantage if somebody is shooting back.
Especially at night because the beam goes right to you.
Lol.. well.. if you're pointing a loaded gun at someone with your finger on the trigger enough to fire the laser sight.. I would think that their precious eyesight is of little concern with regards to possibly taking their entire life.
It's actually not for me, as I ask for a gun enthusiast family member. The thought process is that in itself it would be a deterrent.. and a fun toy during the day for target practice.