Thanks for sharing this. Is yours regulated or can you see a noticeable difference in output during the depletion of the battery?
No runtime tests as of yet, and even when I do run them, they'll be at low single digits or sub-lumens (what I use 80% of the time). My concern is actually more of it getting brighter as QTC settles/expands over time. This Peak will be a dedicated low lumen / headlamp light for me for its ability to dial in (eventually anyways) just the right amount of low lumens.
IMHO, if you like bright, I would look elsewhere since 1) it's not that bright, relatively speaking (maybe the Ultra-X is much better?) 2) the battery crusher design makes me cringe dialing in max when using lithium cells and 3) the QTC pill, and foam surrounds, theoretically will deteriorate faster under full compression cycles.