Iāve tried. I have an impression that many people have.
Yep, XP-L, XP-L HI and Nichia 219C emitters all work great in that reflector with no adjustment needed!
After thinking about this a bit more I dont think simply changing the battery tube is enough to sell me personally unless they make at least some other change.
I would want the driver area bored out to at least 20mm and potentially a change to the way it is assembled would be nice.
I am hopeful shaved XPLs (I bought from Arrow) will get the throw just a bit further out there than my current set of (also shaved) XP-L2s. I also bought a set of XPL-HIs from KD which I should have in about a week to also check out. The shaved XP-L2s are impressive as they are but from all Iāve read re. XPL Vs. XP-L2s (when over driven), these older XPL leds will be hitting their āsweet spotsā with what I can get through this host current wise.
Lexelās TA NarsilDs run about $15 each (I have four) and so with emitter cost at $3 each (XPL or XP-L2), and host for $12 (plus a few springs, wire, etc.)ā this is a heck of a custom light for about $37 bucks!!! I paid a bit over $5 each for KDās XPL-HIs so add another $6 to that build. Just saying that for the investmentā these are GREAT the way they are.
But this is BLF, so Iāll find out what works best for me with SIX hosts now in the hand. 
I ALSO will be building a direct drive C8F on one of the host kits. That will be the final gun version (dedicated to ONLY gun use and triggered by Lexelās ālosslessā pressure āFET tail switchā). With a tail spring bi-pass, and the usual tweaks, Iām hoping to run about 18 amps through three (probably XLP HIs) straight off the battery. :smiling_imp:
What Iād want change wise?: SAME 1ā battery tube, a boost driver (probably 20mm), larger battery, and XHP-35 HI (or shaved XHP50.2 for tweakers like me) that would pull about 15 amps, and run the larger leds without over-driving them. 4500 - 5500 lumen maybe?
The rate you are dreaming you might not even need to load the gun. Put the pressure switch right on the trigger
Dreaming is what we do- before we do it, right? 
Butā¦ I know that NOT a lot of people want a screamer in a C8 with the short run times and heat.
Sofirn isnāt into the esoteric market, but the solid budget performance marketā so the C8F is kind of a surprise in that regard, but for the $35 or so it sells forā it holds itās own.
Iād LOVE to put the FET on the trigger, but it will have to work in the handle or rail- I am still working with the (my) ergonomics there.
Would anyone be willing/able to post beam shots with the C8F triple reflector and various LEDsā¦ perhaps in comparison to a Q8?
Cheers!
Yep, Iām on the hook for four builds Iām working on- two are done. About a week away.
And I REALLY tried to get one of those ThorFire codes floating around last week (to get a Q8 for UNDER $45!!!). If someone sent me a code, Iād order one tonight and promise to compare it to my final builds. Any takers???
But it would have to be a great deal (with a code) as I just dropped my MAY allowance on a big order from Sofirn THIS month. As my wife says, āI HAD to get it to SAVE money!ā
Anyway, Iāll put up pics and speeds/feeds for each C8F. This list is a few post above though if youād like a preview.
New poll:
(You can see this post also in the OP)
I talked with Sofirn a lot and they sent me some 3D renderings how the 21700 and 26650 flashlight will look like next to the old 18650 version. I want to ask everybody who interested in these new versions to please post what battery size you prefer from the two new options and how many will you buy as a host or as a complete flashlight. You can see tailswitch on some of them but that and the head design is not sure they staying like on these pics. So the flashlight maybe will be dual switch or maybe not and the head maybe change to more finned design or maybe not. This poll is only about battery size but you can tell your opinion about dual switch or only side e-switch. This is not a groupbuy! Just some help for Sofirn to choose which battery size to go next. I also adviced to make some knurling on tube and if the light will be side switch only I think a tailcap like the SP32A will be more stable tailstanding then the C8 without the switch. After some time I count the votes and forward them to Sofirn.
I donāt have any 21700 flashlights and batteries but I holded one in hand a few weeks ago and that is the best diameter I ever gripped. Feels very comfortable and not too big. So my vote is for 21700 because that is the future 18650 I hope.
Here are the 3D renderings :
The three battery size next to each other:
This is all 21700 and dual switch what is they prefer and to keep the C8 design but If the pollās result show something else, they will make it that way:
As requestedā¦ā¦
I prefer a 26650 versionā¦
I would purchase at least.
- 2 complete lights
- 2 hosts
Dual switch preferred.
I prefer 21700, because it smaller, lighter, and it have near the same capacity than 26650. I also prefer the dual-switch one.
I wanna order a 21700 one, aprox two pieces.
prefer a 26650 version
would buy 1 light & 2 hosts minimum
I vote for a 26650 version. I love my original. Great light. Also I like the dual switch.
I prefer the 21700 version.
And I prefer to get rid of the typical C8-styling and add fins. Also there is too much aluminium in the head, it makes the flashlight unneccesary heavy. If that unneccesary āmeatā is converted into fins, the C8F can be run a couple of seconds shorter in turbo but can maintain a higher output level in the long run.
Iā prefer 26650 - My chargers cannot handle 70+ mm batteries and I have a number of 26650 Li-ion cells already. Plus I have a big hand. 
I prefer the side switch only version.
+1 request: conversion tube for 18650.
Vote for 2 version both 21700/26650 with tail switch + smooth stainless steel bezel . I want 1 each as complete light.
21700. Would buy 1 but more if they made other changes as well. Host only for me
Same with me.
I want side switch and tail switch
Prefer 21700. Strongly prefer e-switch only.
Count me in for 26650 variant (would prefer single switch, as tailcap can lock out mechanically).
Probably Iād take 2 hosts at least.
Further changes requested (not so closely related to the poll):
1. There is a very thin, but noticeable ring in the beam pattern, the reflector design would need a revision (I would also prefer fixing the reflector by the bezel, not by the back spring).
2. Possibility to use larger driver boards as well (if possible, with keeping original driver compatibility e.g. by an adapter ring pair)
3. Better heatsinking/heatspreading abilities for more prolonged high output usage.