I have to agree with JohnN and Hacksaw regarding the Gerber Infinity. I really like this light. The lithium batteries certainly cut down the weight and extend the runtime, but even with a standard (or a depleted) AA this is a nice really light to have on your person. The unit is also legitimately waterproof. The finish on the aluminum case is pretty easily worn when the light is in your pocket with other items. Strictly a cosmetic issue. Also, I was concerned about the exposed bulb (albeit recessed), however, that has not proven to be an issue at all even when carried in a pocket with small hard objects.

Alex, I really look forward to the results of your runtime tests in a chilled environment.