I have been considering them as well...cheaper... just not sure... I also like the Tac lights/laser but don't know about repeatability of them being taken off for ccw and put back on for duty/home def...
I have a Lasermax in my G26 and it is VERY accurate. It's also nice as it add no bulk to the gun. At the 20 yard line I can keep about a 3" group rapid fire with the Lasermax on holding the gun just below my shoulders and only looking at the blinking dot...
I can't tell you about its accuracy in a Glock, but it shoots very accurately in my Colt 1911 - out to about 15 yards (I have a bit of difficulty seeing it beyond 15 yards during the day).