Ok, I may have been wrong. According to _the_'s review, on Eneloops the Cyclone draws 0.53A on medium which I calculate 4.3hrs runtime on 2300mAh NiMh's. The Cyclone won't reach max output on NiMh cells (I'm estimating 600 lumens based on _the_'s mAh's) and the level it will put out won't last long. The 4AA's can reach max output and last longer. I estimate the Cyclone at 200 lumens at it's 0.53A tailcap current, while the Jetbeam PA40 is rated 468 lumens on Hi (yes less lumens) for 2.5hrs and 220 lumens for 6 hours.
-Garry