Looking for a lightweight single cell headlamp

[Buck91]

Looking around to see if there is anything out there worth replacing my Thrunite TH20 (XPL neutral) with. My goals are
-light weight
-good balance of runtime and output ranging from a multi-day moonlight to a high/turbo somewhere between 100-200lm. More is great as long as the UI is easy to use.
-great tint and cri combination
-flood'ish beam profile. My old H50Q5 is pushing a little too floody. The TH20 is a good reference but even floodier is just fine.
-excellent water resistance (ipx8, suitable for swimming and canoeing)
-Battery configuation. I'm a huge fan of single AA lights for simplicity but anything that can be fed a choice between primaries and chargables is fine. I can handle nimh, lithium primaries or li-ion. I could probably get down with a cr123/18340 light this time around, actually. Larger than what I'm looking for but I'd be curious about a 18650/2xCR123 light as well.

So I was fumbling through my over night bag and started playing with the Black Diamond Cosmos headlamp I got from Massdrop a while back. While its not exactly a flashaholic's favorite setup it is light. Definitely lighter than any 18650 but feels like it might even be lighter than my Thrunite TH20 or Acebeam H40 (the later being an absolutely stellar headlamp but way to spotty beam profile). Interestingly, the H502c as well as the H53fc does seem to be lighter, but I'm unsure what the real world difference between the luxeon T and the XPL emitters would be. Not a deal breaker but I do prefer a centered LED as opposed to the offset side style like many are making these days.

 

[Zak]

Put some DC Fix on an H40.

 

[LeanBurn]

Thrunite TH20 dead?

 

[Lynx_Arc]

I'm an avid fan of the 18650 format but it isn't that lightweight typically the heaviest and bulkiest of the 1 cell headlamps. I went to the format because I truly needed a headlamp that could sustain a 50-70 lumen output for 8-10 hours a day and decided I did not want an external battery pack or one mounted on the back of your head because I often used a headlamp in tight spaces and laying under a vehicle too. I decided that the 16340 and CR123 and 1AA and 2AA headlamps were right on the edge of my needs with outputs barely in my range and overall runtimes also barely within range and figured that actual runtimes had often the output fading way below my target tunning down to dimmer than desired. Only the 18650 format had enough energy to sustain more than my desired output for longer than needed.
I got about 120 lumens for 10-15 hours and can often run 2-3 days in use without needing a recharge using all but moonlight modes.
I've found on occasion I need to step up to the 400 lumen high mode for 5-10 minutes for range or to see tiny things due to my aging eyes and turbo to see in dark spaces or light up large areas for a few minutes with 900 or so lumens the turbo is useful but I could get by with 400-500 lumens but I've found that 18650 headlamps with the highest mode of 400-600 lumens that mode usually is turbo and the lower modes are adjusted accordingly leaving your low and medium modes lower than a higher output headlamp giving you a low too low and a medium lower than needed with a high mode brighter than needed sacrificing useful runtime.
I've found that until you get used to the modes on a headlamp and force yourself to use lower modes and get adjusted to them you could find yourself running the headlamp on higher modes than you truly need to and regardless of the headlamp find yourself not having enough runtime to get the task done.
I did a lot of work with my old Rayovac 1AA headlamp at about 30 lumens but got very frustrated at having to stop every 90-150 minutes to change batteries when it blinked and either went dark or ended up with a single red LED lighting the way.
I typically take off the top headstrap on my headlamps and 18650 headlamps they do bounce a little if you are jogging running probably best to keep the top strap on.