Phaedrus, you're absolutely correct about the disparity between AAs and CR123As in terms of mAh, but Watt hours are more important for capacity. There we see that a 3V CR123A with 1550mAh has a measurable advantage over a 1.5V AA with 2700mAh.

The voltage difference means that the "pill" in the flashlight doesn't have to bring the voltage up as far to meet the needs of the emitter, so the effective output and runtime is tremendously better for CR123A flashlight versus one using AAs.