The US Border Patrol tested laser equipt handguns with the possibility of issuing every Agent one. What came out of the evaluation is that they added little if any practice use for most shooting situations. They actually slowed down shot times as agents looked for the dot, not every shooter every time, but enough to cause concern.
I agree with Gaerek, They do have a place in unconventional shooting positions, but so does proficiency. Technology is no replacement for skill.
My rifle and pistol are tools, I am the weapon.