There is nothing really advanced about the Surefire M6 guardian it's pretty simple from what I know of it, and I would almost go as far as to say that the Maglite is more advance due to its focusable cam system. There is more to the 10X dominator, thats for sure. But really, they are all just fancy tubes.
The funny thing about incandescent lights, is there really isn't anything advanced about them. They are just a package, a tube of sorts in which to mount a bulb and some batteries for practical use. Those only REAL advancements made in incan tech, is in the bulbs themselves. I would hazard to guess that we have already mastered the Incan light bulb making it as efficient as can be. Now it's jsut a question of what rated filament do you want it what size envelope on what kind of base to match your application.
The only other advancements to be made are in Battery and Reflector tech, but those are both advancements to be shared with the LED.
If you go to your nearest whatever store, Incan flashlights are dropping off the shelf in favor of LED for the average Joe, but for the time being Incan has a while to go yet, as it still has many practical uses in the high end market until LED matures to match Incans wide spectrum output.
Meanwhile, fluorescent tech is improving in leaps and bound to replace Incan in the household and workplace for room lighting. I'm quite impressed by the new 6700k T5HO offerings.
HID seems already to be replacing incan for extreme high output applications and with tweeking are more capable of delivering wide spectrum light then LED.
Sadly, I do have to admit, the incan clock is ticking. A day will come when a LED can do everything and incan flashlight can do and better. Some would debate that day has already come.
IN other news, we still have quite a few decades to go before Incan bulbs go way of the Carbide Lamp, which STILL can be had today with the right sourcing.