And the race is on! 300 lumen XC1-B. Same form factor as far as I can tell, but a new user interface. Toggle for momentary on, toggle quickly for constant on. This is probably the biggest improvement for the light. I still think it needs a deeper reflector though.

Ambidextrous switching provides both momentary- and constant-on activation options. Momentary-on activation is achieved by placing your support hand thumb on top of either of the two rear downward-activated switches and pushing down. The XC1-B will stay in momentary mode for as long as either toggle switch is depressed and held in the on position beyond a fraction of a second. Constant-on activation is achieved by quickly tapping either one of the momentary switches. To turn off the constant on mode, quickly touch and release either toggle switch. It can also be achieved by using your support hand to push the center crossbar switch from left to right.
http://www.surefire.com/illumination...aponlight.html