I decided to do a little testing with Crimson Trace's LG436 on My Glock 19
Targets two IDPA tatgets 9 feet apart left hand target angled 45
degrees towards shooter
COF start facing right hand target 5 feet away
fire two rounds at body and one round to the head of the
right hand target .
Then fire two rounds at left hand target all while retreating
as rapidly as possible.
Pistol Glock 19 with night sights and LG436 laser
Holster Talon Tactical PDL
Ammo Federal 115 ball
Time Dusk
Cover garment was a 5.11 shirt
Background I have been a competition shooter 30 years
(IPSC IDPA) a IDPA master

results Night sights best 3.37 sec. average times 3.6 -3.8
CT LG-436 best 2.32 sec. average times 2.5-2.7

As it got darker the times with the CT 436 stayed about the same while the night sight runs steadily got slower
The difference between was night sights and the laser was quite dramatic I could move faster and make good hits much easier than with night sights. Getting good hits with either sights was not difficult at all, it was just faster with the Crimson Trace LG-436 laser.

Mike