Alright - Looking at getting a new tactical flashlight for the duty belt. What is the difference between the Surefire Z2X LED, Surefire G2ZX LED, or the Surefire AZ2 LED. They seem like basically the same flashlight, what am I missing? Also - is it really worth it getting the LED over the standard bulb. I have the Surefire Z2 combat light right now with the upgraded bulb. I like Surefire and have been pretty happy with my old one, don't want a re-chargeable. Any suggestions that I am missing for a small flashlight similar in size to the above?