All things considered, I carry a Princeton Tec headlamp. I find headlamps are much more versatile as they free up both hands to accomplish tasks both in camp and out on the trail which at times can be much more cumbersome or impossible if one had to hold a flashlight in one hand.

The particular model I have has a rated burn time of 50 hours on high, 90 hours on medium, 146 hours on low. On flash, the rate is 96 hours.

As these are marketing ratings, I view them as such and find that the real world burn times are about 75-80% of claimed. Even so, there would not be very many times, if at all where the average person would need this amount of burn time unless they were severely stranded for days/week(s) at a time. Even then and depending on circumstances, by nightfall, your shelter should be setup, firewood gathered so there should be little need for light. Although it goes against almost all survival knowledge, traveling at night unless it is definitive life or death situation would not be wise, but if it were life or death, then a reliable headlamp flashlight and good batteries are mandatory.

Keep in mind that there is big difference between survival and recreation walking/traveling at night. Many times, we have headed out in the early pre-dawn dark on a trail to bag some peak so that we could get back down safely off the mountain by the end of day nightfall.