For me, a single 21700 light doesn’t really justify getting into a new battery format; I’d rather have a 2x18650 thrower vs a 1x21700 as the runtimes are comparable.
Also, I just prefer the classic flashlight aesthetic of long tube, big head. And since a Thrower with 60mm+ head is not a pocket light, there’s really no point in having a big head + short tube format.
A lot of that has to do with the Osram LED. It gives lots of throw, but not many lumens. If you evaluated lux vs runtime, I’m sure you’d have a different opinion. The beam on this light would be super narrow and intense. 1900m equates to ~900,000 lux. This is what they claim, but I would guess its closer to ~800k sustained. The Acebeam T28 uses a Cree XHP35, which has considerably less throw, but a much larger spot and more lumens and lumens/watt.
In addition, running 2 cells in series to a 3V emitter is almost always going to be less efficient because the driver has to work harder to convert the larger voltage gap. The trade-off though is full regulation. Let’s face it though, will you really use this for 2 hours continuously? And if so, spare batteries are probably the smallest part of your gear you are using in such a situation. 21700s only have 50% more energy than it’s 18650 brethren. I don’t know how much you expect, but that’s the most it’ll be.
I would think of it as a two mode light honestly. What you have is Turbo, Hi, Lo. Hi will give ~80% for 2x the time and 1/2 the heat of Turbo. A single Lo mode is all that really makes sense in this form factor. If you want something with less power and reach, a smaller light will serve you well. This is a purpose built thrower. A light that you’ll only want to use on max. I think if you had the chance to actually use lights of this type, you’ll quickly agree. Once you exceed the size/weight threshold of “comfortable to carry or pocket”, more than two or three modes is a waste and will never be used and just get in the way. It’s like someone using a machete to peel a potato.
Between the 1500lm Highx1hr vs 350lm x 8hr mode, I use the 350lm mode the most. To me, the advantage of a thrower is that its capable of very good range and performance at medium lumens, with the ability to last all night due to the multi-cell configuration.
Based on the performance of the Barracuda at 350lm, I’d really like something like a ‘Super ’Cuda’ in 21700, that could do ~500lm x 8hrs.
I just don’t know what your application is. What is your environment, objective, and targets to be illuminated? Do you drain a full set of batteries in a night, or possibly even multiple sets? To me, needing a super thrower like this makes me assume very distant targets, where spill beam never touches. This means that spot size or beam angle and center-beam intensity are the specs that matter. Lumens in this case wouldn’t be relevant. Maybe that’s why I’m confused.
Your last comment tells me you do have field experience with these lights, and that you understand the value of Lux/W, but maybe never thought of it in those units. The reason you like the thrower lights is because you can get the required light on target with less power consumption than a with a less focused flashlight. Now consider that between (I’m guessing you have the v2 with XHP35-HI) the Barracuda and X Pro, that there is a 5x difference in beam intensity. This means throw at 150lm setting is aprox equal to the Barracuda on 750lm. If your targets are at close range or very large objects, then a higher lumen, larger surface area emitter would be more appropriate.
Honestly though, I think 26650’s get a bad rap. The form factor can be nice and they have higher max capacities than 21700 cells. They aren’t better for pocket EDC lights, but not all lights are meant for that anyway.
I actually really like them, and the 26800s too. I have very large hands, so it feels better to me to hold on to a thicker diameter flashlight. The increased length of 26800 lights is a welcome change, too. Plus, the increased runtimes are nice. I won’t be throwing away my 18650 or 21700 lights any time soon, though.