Isn't the E01 supposed to be a solid 10lm reference? My EZ-AA (cool white, so rated at 10 by Nitecore), running on an Eneloop, matches the E01 as near perfect as I can tell in a ceiling bounce. IMHO, no way it's 15 lumens.
High was a little disappointing at first -- then I remembered when I got it out of the box, I had grabbed the first AA that came to hand (an alkaline, and a partly used one at that) just to fire it up. Found a charged Eneloop, popped it in, and now bright is brighter. 😀
For another reference point on the brightness of high: it's brighter than an Akoray K-105's high from NiMH, but dimmer than the K-105's high on LiCo. (My K-105 will go substantially lower; although I've heard reports that some K-105s only go down to about 15lm, I think it's an issue with programming technique. The high is programmable separate from the ramp, so it should be a solid reference.) I find the Akoray a convenient comparison because it's beam profile is the most similar (almost identical, even though it uses a substantially larger reflector), reducing any potential variations in ceiling bounce.
Cool thing about it: the head knurling is grippy enough to use momentary-on by twisting it just off, holding the light against your palm with the head between thumb and forefinger, and pulling it down to take up the slack in the threads. Better yet, you can pull the same trick with high, by twisting it just down to low, and using the same technique (a little more forcefully, since the foam is more compressed). For some reason, I find walking around with it on low and randomly giving momentary-high bursts rather entertaining.
EDIT: One more thing, on mine, there's about 2/3 of a turn from off/low to low/high. Not bad, although it could be less -- it's easy to feel the increasing pressure just before it goes high, so there's no way one of these is going to have accidental overruns into high, even if it had only 45 degrees.
