I like the CTC grip lasers because they come on when you grasp the pistol and don't have to fumble for switches, etc.
HOWEVER, laser's can become "Crutches" when people shoot. Many people will tend to "shoot towards" the light, forgetting how to aim. They're great for "reflexive" defensive shooting situations where you may not be able to acquire the sights fast enough. But, the laser should always be considered your "Backup" when you practice and the "iron" sights should always be your primary.
If you do install it, zero it and practice with it while trying to ignore where the point of light is and concentrate on your sight picture.
After the laser is zeroed (say for 21 ft), then practice shooting at shorter or longer distances to see where the point of impact is vs/ where you're laser is zeroed. This would become your "sight picture" when you're shooting at a distance other than the one you're zeroed for.
Not sure if that makes sense, but there you go. It's much easier to express when I have a pistol with a laser on it.
D