Depusm
While i have a Defender II, i do not use it at work, just prefer my Raider i am afraid and the Defender really can't compete with the Raider's output. That said if i was carrying a Sniper or similar 6V light i would definately replace it with the Defender.
I am not 100% convinced on the useability/purpose of the new 2 stage high/strobe, i much prefer the option of a low/high configuration. I also don't like the idea of having to click between the modes, 2 seconds can be a lifetime in some situations, the Defender II offers a great high/low with a simple UI, the twist of the bezel required to change between modes is small enough that with a little practice you will quite easily work out high and low starting points hence make it almost impossible to start in the wrong mode.