I have the Crimson Trace laser grips on 3 of my handguns. A Glock 19, a S&W 640 snubbie, and a Taurus tracker .357. I have them sighted in for 25 yards and I can shoot groups a lot tighter using them than I can using iron sights. I haven't had any problems with them losing adjustment and I like how they turn on instantaneously when the grip is squeezed. I also have a S&W bodyguard .380 with the built-in laser under the barrel. It gets covered with powder from the muzzle when shooting. Not sure if the internal rod lasers do that also.