The brightest Fenix is currently the P3D using a Lumileds Rebel giving 200 Lumen for 1.8 Hours using up 2 CR123s. The Fenix is 4 time more efficient is also 10 times cheaper and quarter the size and weight of the M6.
Yes, as I said Fenix has a better brightness per cost ratio. But, the M6 has far output than even that Fenix in my testing. Should an M6 be part of any emergency kit? No, but I can see it being in the rescuer's kit in some cases (when someone else pays the bills).
Also keep in mind that “lumens” can't be compared between Surefire and Fenix since they are measuring different things: it's apples to oranges. That Fenix is about 160 lumens per Surefire's methods and the M6 would be over 700 lumens per Fenix's methods (Fenix doesn't actually measure output but rather computes it from LED and power supply specs). Nothing wrong with either method; just noting that they are quite different.
Or how about the Microfire Warrior III K3500R giving 3500 Lumen for over 50 minutes using a rechargable lithium ion cell. It is only slightly larger and heavier (12 oz) than the Surefire M6 and not that much more expensive. This will beat the Surefire M6 hands down.
Not if it doesn't work when you need it. My experience with HIDs is that they are relatively fragile and need careful handling compared to other emergency gear. You can't drop a HID 3' onto rock and expect it to work (Surefire Beast is an exception). There are a lot of other variables between HIDs that are relevant to emergency use; it's harder to analyze HIDs for this use than it is other lights.
I can't pull up the Microfire K3500R web page right now – I just get a page of Chinese glyphs that appear to be an error message. Last I heard this light wasn't actually out yet?
I have a Wolf-Eyes Boxer 10W/123 which I keep in my car's glove compartment when not in use. It is all of 6.3”(!) long and uses “standard” CR123 batteries (“standard” meaning the same as my other lights and the same as my emergency battery stash). Another interesting HID I've owned is that Underwater Kinetics LC-100, a 10W HID dive-light that works in air too. It uses eight C cells and has other disadvantages but I can see some people might have a use for it in as a lake emergency light.
The dozen or so lithium AA's I bought are still in their packaging. I bought them for extreme environments and have a set in my kits with the flashlights they'll go in.
I agree this is reasonable. Another possibility might be the Sanyo Eneloop NiHM - rechargeable yet a long shelf life (over a year). I'm not familiar with them.
Comparing CR123's to Alkaline AA's is comparing apples to bananas. CR123's to Lithium AA's would be a much better matchup.
I was interpreting other's comments in the context of Alkaline cells. That may not have been a good assumption.
Folks over on CPF rave over them. Maybe I got two duds but I bought two (one for my wife and another for me). They both went down in a couple of weeks. I sent an email to the company and was given a fix for the problem. A week later it went down again.
I haven't noticed any trend in posted problems with Fenix, other than the tail switch. Most of their problems seem to be in the switch. Overall they don't seem better or worse than other manufacturers.
To give background to my opinions, I'm not impressed by lumens any more. Anyone can build a bright flashlight. If that's the goal then I'd go to Hong Kong retailers like
http://www.dealextreme.com/ or
http://www.kaidomain.com/ and get the same lumens as Fenix for half the price. It's things other than lumens that seem to separate the good from the bad these days, especially in terms of emergency use.