An excellent choice for a CCW or personal defense gun. I was opposed to them until I purchased a gun that had them, afterwards I was sold and have since added them to several of my guns.
Generally speaking, mose personal defense situations occur at night, or during low lite conditions. The laser site allows you to hold the pistol on the hip while both eyes are on the target, all you have to do is place the dot where you want it and pull the trigger.
Like GB said, my shooting improved with the laser, and under most conditions they work equally as well during the daylight hours. I can see the dot out to about 40-50 feet depending on how bright the sun is. Out to about 20-25 feet it is effective even in bright sunlight. As for a dead battery when you need it, the used gun that I bought with the grips already installed is well over two years old, and the laser seems to be as bright as ever. If you are truly concerned about a dead battery when you need it, then establish a preventive maintenance schedule and changing the batteries at a set time, depending on use. Batteries are not expensive, so once a year would not break the bank, and that would provide the peace of mind to have confidance in the gun.
Antother very important plus. It was easy to have my wife and grand daughters shooting on target in a very short period with the laser grips. In my opinion they are well worth the price.