Well, I did a quick emitter swap on this one tonight. I put in an XM-L2 T6 1C on a 16mm copper SinkPAD. Beefed up the emitter wires to 20ga.
Drives around 3.6A on 26650.
Output is 1070lm at start, 1022lm at 30s.
Throw is 27.2kcd after 30s.
It is definitely a decent light now. It handles the heat really well. After almost 6 minutes, the head temperature was about 40C, and output dropped into the mid 900’s.
Great review!
It must have slipped by me, I saw it first now. I was waiting for you to review that light. 
The red tailcap did not look as good as I had hoped, but then again. DX pictures often seem over saturated.
Nice light, especially after modded.
Is there a reason you used XM-L2 T6 instead of XM-L U3?
I’ve never directly compared them, but I seem to get a bit more from these XM-L2 T6 emitters. On paper they should be similar though, good point.
I swapped out the tailcap, not because of the red, because it was too squishy.
Thanks for the info…
And so the search for a nice red tailcap continues… 
hehe…
I'm glad to see this is a great mod host. A 17mm driver would have made things simpler, but a copper washer should work fine.
Thanks for the review.
The Ultrafire version is a tiny bit less at $19.80.
http://www.kaidomain.com/Product/Details.S021554
Thanks for the info relic38.
I'm not even going to bother with a review for this light. You and garrybunk did a good job. I wouldn't run this light without adding thermal paste under the MCPCB, and at that point the review is already somewhat dishonest, so I'm going to go straight for the mod. My experience is almost nothing so far, but I think this will be a really good mod host if high output is more important than fine machining and flawless anodization.
I love the room for the 20mm MCPCB. The ~21mm driver makes it a little more complicated since I'll have a floating driver. Hopefully there's enough depth for the floating driver and some extra thermal mass under the back of the pill. This thing has so many threads on the pill and head. I'll see if that helps with the thermal path. I'm planning on pushing over 4A with this project.
The Windfire version is even cheaper..
On top of that, maybe WB have a nice coupon code for August too??
leaftye, sorry you think something in the review is dishonest. If you can tell me what you think is at issue and I will take a look. I can assure you there is no intentional dishonesty in the review. There may be mistakes or missing information that can be interpreted as such,and I would like the opportunity to fix them. Thanks.
To your point about thermal handling, I believe this host can handle quite a bit of drive current. I am pushing over 4A and have run it for quite long like that. It does get hot, but the heatsinking removes it quickly.
I didn't mean your review was dishonest. I think you were honest.
I meant that I would want to do beam shots and lux testing with the light exactly as delivered. Since this light doesn't have thermal paste under the MCPCB, that's how I think it should be tested. If the lack of thermal paste means the LED burns up after 5 minutes of taking beam shot pictures, then that's how I'd review it.
Your review indicates that you added thermal paste afterwards, which would make it as honest a review as possible.
Thanks for clarifying, leaftye. I tested the light in stock condition, but I do not normally do long term tests of the light in stock form. Because I’m a modder at heart, my reviews tend to take a mod-oriented approach. That is why it’s more of an internal tear-down style of review. I reserve comment space for long-term tests, but I always end up modding the light before doing them. 
I do have some changes coming for future reviews that should provide a more rounded view of the lights, for modders and non-modders alike. I’ll keep a lot of the same format, but expand on it in a few ways.
Thanks again for doing this review that gave me the push to order and mod this light.
I'm almost done modding mine. A few things I noted.
As expected, the driver was the hardest part.
Like your F13, mine has a LED centering ring that blocks a lot of light. I tried removing it and seeing if I could get the LED to sit deeper into the reflector, but that didn't seem to work. And again like you, I installed a lower profile centering ring. EDIT: I ground the sides of the bottom of the reflector, and now it sits down all the way. The beam is now very ringy.
The reflector was shorting the emitter wires. I was using 18awg leads and a 20mm Noctigon MCPCB. I'm currently putting plastidip on the bottom of the reflector. EDIT: The leads were ripping through the plastidip. I taped the bottom of the reflector with kapton tape, and that worked.
With a floating 12*7135 Nanjg105 behind a 21mm contact plate and those burly 18awg wires, there wasn't room for adding thermal mass. I had been hoping to add 2-3 copper pennies, so it's really disappointing to add zero.
The contact plate doesn't sit in the pill very well because it's 1mm too small, but the retaining ring seems to do a good enough job at holding it in place and grounding the contact plate.
I added wire to the tailcap spring, but skipped the other spring because I just wanted to get done for now. EDIT: Added the other spring while waiting for the plastidip to dry.
A Trustfire flames protected button top 26650 fits. It's my longest cell. That's a good for any light, but especially one with springs that don't compress as far/easy because of added wires.
The tailcap end of the battery tube has some anodization. I'm going to grind it off to ensure full contact with the tailcap.
It doesn't warm up as quickly as I thought it would. I don't think I'll like the reason. I may have screwed up stacking 7135's, or MCPCB isn't sitting flat, or I didn't connect the driver and contact plate well enough, or the thermal path isn't nearly as good as I thought it would be. At best it's pulling 4A, but I'm not appreciating the output without the reflector installed. I'll try to determine the tailcap current later. EDIT: It warms up now. I think the MCPCB wasn't transferring heat effectively until the reflector was installed and pushing down on it. Or maybe it needed that other spring wire installed. EDIT 2: 3.44A at the tailcap, but battery was only charged to 4.1V.
I'm going to order 22mm copper washers to directly mount the nanjg105 driver to. This will reduce the driver stack height and allow some thermal mass to be added. Switching from 18awg wires to 22awg should provide even more space in the pill. Screws will also be added to hold down the MCPCB...no Fujik for this light.
Go for the Paisen U2 z6 at WB,only $18.. and 2 months ago it was $15 with the 15% discount, last month it was 10% discount.. this month?????no discount ??
its the exact same... I like it.. honestly.
I'd wait for a discount again, otherwise I'd prefer the Windfire because of the nice lanyard.
I`m pretty sure mine also came with a lanyard.. I believe it was dark green.
edit: yes.. I`m sure, I have the exact lanyard in front of me, same as pictured with the Windfire.
You know what I have attached to my flashlight now? That exact lanyard. It was on the table where I left it when I unpacked the light. It's been a long night of modding...
:D
The lanyard that came with it wasn’t bad, IIRC.
leaftye, looks like you got a decent mod going there. As for heat, the host handles heat well, however, if you have good thermal contact from emitter to host it should start to warm up quickly. I will note that you may not notice it by hand for a few minutes because the head has a deceiving amount of mass. Using an IR probe, I can first detect warmup in about 10 seconds; by hand it takes about a minute.
Thanks a lot for the review! Frontpage’d and Sticky’d.
see
Ultrafire F13 at $9.00 - with Coupon Code - Gearbest