Back last year, I bought a few CR123A based led lights which were amazing totally outbeating my six cell Maglight. I was amazed and delighted until the big storm. I went out to get batteries at the store and the only ones left were AAs. No Cs, no Ds, and not a CR123a in site. Luckily, I bought a 12 pack from Surefire months ago and so I did not run dry although the power was out for about a week or so.
I also started reading about the effects of bad CR123a batteries which became small explosives and hazardous waste when not stored properly. There are even CR123a batteries out there which are fakes of the better made ones (Panasonic, Duracell, Surefire, Streamlight, etc.) which explode after a while. CR123a batteries can be hazardous and turn your flashlight into a pipe bomb.
So I found what I believe is the ultimate flashlight for tactical purposes. The Fenix TK41.
http://www.fenixlight.com/viewnproduct.asp?id=89
It uses 8 AA batteries and I saw on Amazon 45 of them going for $12. The AA batteries are the only ones I found at the area stores right before the hurricane and there were plenty of those AAs in various electronic items around my home. In comparison, other batteries were certainly not available. The CR123as can be found at a store, but they are A LOT more expensive at the store then online. Even the ones online cost about $22 for 12. So I get 3 reloads with a $22 12 pack with my TK35 which holds 4 CR123a, but I get 5 reloads with the $12 large pack from Amazon. The TK41 is less costly to operate in the long run.
The TK41 is about 3 times stronger then a six cell Maglight and about the size of a standard 2-D cell flashlight. You can stick the TK41 into the trunk of a patrol car on a hot day without fear the batteries might turn your cruiser into a flaming wreck or a site for Hazmat cleanup crews. If I was buying for a large law enforcement agency or disaster response, then every single person would have this one.