I actually have both of the lights you are referring to. If you do a search you will find a thread I made in regards to the Zooming C8 Host with an XP-G2. Whilst the UF-T20 cant focus as tightly as the C8 it is better in every other aspect. The lens is a proper glass lens with a deep convex. Whereas the C8 is a thin plastic lens. And the overall quality is much nicer. I would say definitely get the UF-T20.
I got them both from wallbuys.
Well it looks like I am the only unhappy owner of T20 here lol.
I ordered my T20 from Manafont and the main problem with my T20 is the very poor focusing, in full-zoom the die shape is still appears round! The lens is sitting too near with the LED. Note that I am talking about complete stock condition now.
Next I tried to modify it. I added a C8 o-ring under the lens to make it sit further out, and the focusing work like it should. In stock condition the head is locked with the aspherical lens when fully de-focusing it, however after adding the o-ring the head will drop out when fully de-focusing it, the head has finished the threads but the bottom of the lens is still far away from touching the tube to prevent loosening. It’s a bit difficult to describe here unless you have a T20 in your hand and play around with it.
So I figured that adding o-ring is not really a good idea, and then I use the Fasttech brass pill instead since it has a complete flat area and I thought this might allows the LED to sit lower. But the focusing issue still persist. The other problem with my T20 is it has unfix-able flickering issue. I have other modded C8 and the internal structure is basically same as the T20’s but I just cannot fix it. Have tried different drivers and have everywhere checked though.
Not sure if I got a dud. Now I just leave it sitting far away from me and might harvest some of its parts for the other projects. T20 is a complete failed project to me.
Dunno bout the focusing, but I've had flickering - had to really tighten the tailcap. Think it would help sanding or filing or some of the anodizing around that tailcap contact surface with the body. Can't recall details, but I think that's what I did. It sounds like the anodizing problem I had.
I agree, its very impressive to get 135 klux from such a small light and it can get even better with the XP-E2 R4 bin flux .
I couldn’t resist and I bought one !
I have XP-E2(20 ordered 8 left) from illumination supply and XP-G2(20 ordered 5 left) from intl-outdors...
Sometimes XP-E2 beats XP-G2(but that is not more than 5-10%) and most time they are equal at throw but XP-G2 is larger and better emitter.
I have tried and measured them several times in aspherics and reflector.
For me there is nothing better for throw than XP-G2 (I would never buy XP-E2 if I new that before).
IMHO XP-G2 is holly grail of LED emitters.
And I will mention that light meters can vary 20% up or down on results(I seen that). Calibration of them sucks... So probably knowing mine meter would take 100KCD or less in tuned UF T20, and neighbor meter would take 130 KCD :)
I've never seen any evidence of my and rdrfronty's light meters being anywhere close to that far off. In fact we've been in dead-on matching in several modified lights comparisons of our measurements. I've also never saw any evidence that my meter was off from one light to another in throw or lumens measurements. Everything I saw as a result with the meter seem to match up really well in real life situations of beam distance comparisons, outdoors or indoors, by eyeball comparison.
rdrfronty and I have the same $35 meter, and he also has a higher end meter, and again, all I've heard from rdrfronty was how accurate his $35 meter was compared to his much more expensive meter.
Of course I would avoid a cheap light meter, but the $35 meter I got seems to be rock solid reliable.
I have no reason to doubt djozz's claims and measurements.
I have TES 1335 light meter,
I made 8 UF T20 so far driven at 3A XPG2 and they are all around 100KCD or less according to my meter(7 meters converted)...
While we tested friends light meter(generic from DX) showed 115-130 for same lights.
So I believe there is a difference between light meters... I follow several forums and plenty of guys are getting different results for same lights(I will give example of stockOligth SR 95 UT) I seen people measuring from 200 -300 KCD same factory light... (Factory claims 250kcd)
Of course there can be difference between emitters also(it can be more than 10% difference in brightness between same batch of emitters)
My lumen measurements I calculate relative to two 'known' flashlights that I keep unmodded (Thrunite Archer and Sunwayman D40A). My measured brightness of those two flashlights relative to each other are within 2% of their relative factory specifications, so although that does not proof that they are not both off, I think I am on the right track choosing these two flashlights (fingers crossed).
Throw is a different story because now the absolute numbers of my light meter are used here. I can't remember the exact numbers but do remember that the throw of the Thrunite Archer I measured within 2% of what the factory claimed. I just re-measured my D40A at 24.4 klux@1meter (measured at 1 meter and at 2 meter, same throw), the factory claims 24.8, so that is within 2% as well.
For my own convienience, I made a 'reference flashlight' that I measured at 220 lumens and 1100lux@1meter. It is a Ultrafire K10 host with a 2x7135 (700mA) 1 mode lineair driver and a XM-L2 led on a Sinkpad. Because of the low current and lineair regulation it has a constant output from 5 seconds after switch-on until the battery is almost fully empty (I measured that as well). At the start of a measurement I check my set-up with this flashlight.
I will never make exact claims about my measurements, but I think my numbers do give a pretty good idea of what is going on with the output of a flashlight (or led).
OK, I’ve ordered T20 from wallbuys, now tell me what XP-G2 to order for it? 
Will this one fit:
https://www.fasttech.com/products/0/10001905/1311504-cree-xpgbwt-xp-g2-r5-1a-472-lumen-6500-7000k-led-e
xpg2-r5-a1 on order from IOS they have send 27/01 but i have not buy track…. :weary:
I've always been very close to factory specs for throw when they have been known to be accurate. I also won't ever say I'm 100% accurate either but my 3.85A de-domed XP-G2 on copper in the T20, focused well, running a Samsung 20R, measured 3.70A at the tail, is pretty close to real to 135 kcd.
Just re-measured it at 132 kcd, but I do see the tailcap contact problem. At first only measured 108 kcd, then cranked down harder on tightening the tailcap and then it jumped up to a whole new level, and got a solid 132 kcd, measured at 5 meters -- ok down by 2.2% 
, but the T20 warmed up a bit and 20R drained a little with all the re-testing. Usually I like at least 15-20 secs of running, but mostly it's longer in trying to find the hottest spot. For throw, I always look for the max spot, not just the center.
The 108 klux that I measured in my first dedomed XP-G2 UF-T20 mod was at 3.0 A, with a 3C emitter, and nothing tuned at the tailcap, so at 3.85A, a cooler led and a good tight tailcap, 135kcd makes pefect sense to me :-)
djozz - +1 yes, agree totally. I think our measurements are fairly accurate and quite consistent between each other, considering the amps.
I'm sure there are plenty of bad meters out there, either by design or by the chinese lottery, but for the vast majority here on BLF, we try to ensure we have a high confidence level in the lumens and kcd values we post here. Like djozz, I always go back to some known light to double-check the meter.
Yes it will fit but order more of them and install the brightest of them...
Tom you have much powerful remake of t20... 3,7A with samsung R...So there is 30 kcd of difference...
For single cell lights I limit myself mostly up to 3A(I know to solder amc but I don't want to raise current) and mostly use Sanyo 2600 or Pana 2900(PF,PD) 18650 so it will hold longer that kcd than your
imo Several factors can influence on throw(this is for guys that are start to build light):
1. Emitter (among same batch of emitters some are bright but some ain't
, selection is necessary for best results) I did not believe that until I ordered whole batch of them... Vinz is making selection of them also.
2. Aspheric lenses lottery (they are not all the same, sometimes you will get ultra bright and sometimes ultra blurry one which will decrease throw especially with this UF T20)
3. Copper LED PCB(noctigon, sinkpad)
4. Driver. It is up to you to decide(more current better performance but lower runtime)
5. Battery... (forget on crappy fire ones because they can not deploy more than 2A of current to led, only high quality cells like Pana(all of them but especially NCRPF PD) Bad cell will decrease your lux/kcd performance.
6. switch spring(it is ok on UF T20 but on some lights-even premium lights I got to change thinner springs for thicker, and you can actually get boost of performance for more than 15%? Seriously I am not kidding here and I don't know to explain what is happening in thinner spring but it decreases overall performance.
7. Led to pill heat transfer(put hq thearmal paste/glue under the led star like artic alumina or artic silver 5, flashlight will transfer heat much quicker than with fujik for example- I tried that)
8.Night & weather (you will visually see better in clear weather darker nights without stars or moon)-
- I'm telling this because there are to many people out there that can not figure that out. One costumer/older guy came to test flashlight and it was raining hard... With 180KCD light you could hardly see up to 150 meters(shiny rain drops) but man start yelling on me and telling me that I deceive him, that it can not throw 700 meters like I claimed... He said that flashlight must throw that distance no matter of weather
And I could not convince him that this all happened because of bad weather... He upset me so hard that I am not willing to do any tests if weather is not clear or night dark... Human stupidity is incredible...
I’ve found this one on copper and here the tint can be choosen (I’ve picked R5 1A):
http://www.ebay.com/itm/CREE-XP-G2-XPG2-on-Sinkpad-20mm-Copper-Cool-White-Neutral-White-Warm-White-/390629540217?pt=US_Light_Bulbs&var=&hash=item5af355c179
I hope it is OK
This is the best!
Vesturofblood from this forum is selling that... It will give better performance than the one from FT.
In this case I should go with the XP-G2, I long hesitate between the two, also the big advantage is that you can have neutral tint with the same lumens ! Still I wondered how the two compare in real life.
I chose to use the XP-E2 because of the better runtime. On cooper it delivers peak performance at ~2,5A(vs 4,5A xp g2) . Also i chose it for best throw.
Installed in the uniquefire uf-t20 i consider the hotspot to be perfectly usable for spoting at distances over 100 meters.
I just retest my uniquefire tonight, I could see the building at 1200 ! meters being illuminated, true not much light, but it definitely hit it ! The distance to the target building was measured with Google Earth.
This probably means it is over 200k candela throw. This is much higher over the xpg2.
How it is possible i do not know, maybe it has to to with the fact that the beam generated by the xp e2 can stay more focused as the distance increases.
I just picked 2 Uniquefire UF T20 at wallbuys for 21 bucks a change each.
the copper c8 pill’s and the c8 body no more on stock |( i have only the T20
where to buy copper c8 pill now ?