You've gotten a ton of expert advice by people far more qualified than myself already, and this thread is a little outdated, but I'll throw in my two cents.
I've used the FourSevens Mini-ML for a year and a half of backpacking, mostly on the Montana/Idaho state line. I've used it during the fall and winter, and have been extremely pleased. When I was first looking for a lightweight backpacking/snowshoeing light (though I'm not an ultra-light guy, I prefer to keep my electronics on the trail to a light-weight minimum) I was looking at AA lights. However, I made the change to CR123s after seeing the outputs and runtimes I could get on a single CR123 were similar to 2xAA, but with the advantage of being much lighter. I've been using the light with a Fenix headband (as recommended by 'weez82' in post #14, and have found that combination to be a perfect balance (for my needs) of weight, outputs, and runtimes. A very good review on that exact setup can be found on YouTube here [
https://www.youtube.com/watch?v=mGl3XDeR-Ig].
I have found that the low setting (~3 lumen) is perfect for setting up a tarp shelter, cooking, slower hiking at night, and it offers an amazing runtime of about a week. Medium mode is about right for hanging a bear bag or a fast descent at night. I found high not terribly practical, though it can be used to check for eyes in surround vegetation, or for spotting and planning a route up scree. I found that with a general sort of mixed use during the fall (some night hiking, nightly "plant watering" trips, and lots of cooking), I would get about four-five days from one cell. I probably spent about 60% of the time on low, 30% on medium, and 10% on high. During the winter cold I generally had much worse runtime, though this could be partly attributed to the fact that daytime is much shorter, and I spent several nights hiking in some pretty severe blizzards during which I usually ran it at high to make sure I didn't walk over a cornice. I would generally have to change out to a new cell every two days. Cold is probably the most limiting factor though.
In conclusion, I would seriously recommend the FourSevens Mini-ML as solid backpacking light, as it offers (in my opinion) a superb balance between weight, outputs, runtimes, and even costs. A better light probably exists, but for someone trying to stick to a slimmer budget, it's an excellent choice. Best of luck on your trip!
P.S. I stumbled across these CR123 cell holders in my searches for the right light, I found them perfect for keeping my cells organized without adding too much weight to a system. I keep fresh cells positive terminal down, and drained ones positive terminal up, a quick and easy way to make sure you don't swap out a drained cell for another drained cell, especially when you're fumbling at night trying to swap out batteries without a light.
Storeacell SlimLine CR123 |CR123 Battery Holder
Link deleted as per the banner at the top of the page - Norm
