Save your money and leave the Sure fire lights alone. I've used them and they are good and bright, but eat batteries like they are going out of style. And, the batteries ain't cheap. I've gone to using maglites new LED flashlights. I have a 3watt mini mag that is real bright, and the batteries last a long time. Plus, the AA's are pretty cheap to buy. I also use a 2D cell 3Watt LED by Brinkman(almost the same as Mag Lite, only cheaper). It's real bright and the batteries seem to last forever. And, that's comforting when you're in the middle of nowhere and your partners flashlight plays out. He suddenly becomes your best friend. I also have a Streamlight Stinger XT/HP that I use mostly for my job. It is real bright but the battery only lasts about 1 hour. It's rechargeable and the only reason I keep it.
As far as I'm concerned the new 3watt LED's that Maglite and Brinkman are putting out are far and away better, and more economical than any of the Surefire lights.
not all SureFire's eat batteries. I have the E2L and it's an LED model and lasts roughly 30-40hrs and 2 CR lithium batteries and produces a beam of 35lumens. Flashlight runs about $128