Well theres good news and bad news.
The good news is all of my lights are about 25% better than I thought 
The bad news is that my lux meter reads the SN6X-2X at 72,000 cd at 2.06 amps at the tail at 8m.
If it is actually more around the 96,000 region (will try the solder blob mod on my 20Q’s to check its not the trustfire flames playing up), that means I’m EDCing a 170,000 lux c8
Chris
Amanda Thanks for the Fast PM reply. 17track did Not work for me. No Red button. I found SWISS POST Home Page + Pasted the EM TR#. It worked fine, the Light got to USA on 12-2-2013. I looks like the EM Tracking# works on the Home Page but not on the EM Link.
I believe the specs on the Pana PF lists a higher internal resistance than the Pana PD -- disappointing... I'd expect poorer performance for high amps, but since this light is 2 cell with a good regulated driver, I'd opt for high qual protected cells anyway - I'm using KP's.
For reference my protected panasonic 3400s that are from fastech fit snug
I was told by a dealer that the PF had Lower internal resistance and a slightly higher capacity, making it their most High Discharge Capable battery yet.
I want the option of using these in other lights as well and have a couple that protected cells won’t fit in. With the new chemistry being touted as even safer than IMR, I will go with the new PF and see.
Found these specs on the NCR18650PF Panasonic
Battery type: 18650 High Drain
Capacity: 2900mAh
Max Discharge (constant current): 10A
Max Discharge Pulse Current (5-6 sec.): 18A
Full charge: 4.2V
Charging method: CV/CC
Minimum charging current: 0.6A
Rapid Charging current: 1.35A
Nominal (storage) voltage: 3.6V-3.7V
Minimum discharge voltage level: 2.5V
Dimensions: 18.5mm x 66.5mm
Weight: 46g
Button Top: Yes
AC-IR 21 mΩ
With that internal resistance rating, they should be quite good! These specs were at orbtronic.com The length dimension is for a button-top cell, added by Orbtronic and re-wrapped with their name on it.
FastTech states the chemistry as Battery core: LiNiCOMnO2 which is a tweak of the Powerizer chemistry.
Post #6 here: https://budgetlightforum.com/t/-/21369. I recall the PDF spec sheets form Panasonic confirmed those #'s StyXSIS posted there. Here's a press release from KeepPower on them: http://www.keeppower.net/sdp/1356484/4/nd-5804170/144211.html
IS says 35 milli-ohm here: illuminationsupply.com-panasonic-ncr18650pf-2900mah
I could only conclude from all this, it's higher internal resistance than a PD, but maybe this was all prelim specs?
Either way, 21 or 35 is still very good and the better chemistry is a plus. They’re creating an 18650 Powerizer cell that can take repeated cycles and maintain high discharge rates. Remember, the LiNiMnCo chemistry of the Powerizer was designed to power electric cars and bikes.
Pretty sure they’ll run my 6A application quite nicely! And with 2900mAh on tap, they’ll do it for a longer time. 
Either way the resistance does not matter much in this light because its regulated with a buck driver, voltage sag is no issue.
NCR18650B will run even longer since they have about 3000mAh at 4A discharge.
Ive never had an issue with the protection circuit in any of my green protected NCR18650B. And ive tested a few in terms of current and low voltage where I have hit the protection.
On the stock light I see no reason to use PD/PF cells or something with lower capacity....Drain will mostly be 2-2,5A on high which is not that much, and voltage sag does not matter.
Highly modified there might be an advantage to PD/PF cells depending on how the driver works when cell voltage is low. But most likely normal Protected 18650B will do just fine.
On my modified ZY-T08 with buck driver set to 6,4A, high will not work properly when cell voltage is below 3,55V it seems (protected NCR18650B). But I prefer having that type of warning.. That just means its time to change cells if im going to continue on high for some time, or go down to medium in order to extend runtime... Id rather have some type of warning in the 3-3,55v range, than to have regulated output all the way to you hit the protection circuit..
So with that driver in that light, Protected NCR18650B have better runtime and give me a warning in good time.. That is a win win situation. Considering that price is lower too, win, win win. :)
In basically every single XM-L 2x18650 series light NCR18650B is the way to go (IMO)... Great runtime, great price and with great performance.
+1 RaceR86 - on that modified ZY-T08, is is modified from parallel cells to series? Big difference there... Also green protected Pana B's? Where were they from? Believe Scot got his from FastTech and 3 out of 4 failed, but we don't really know the nature of those failures, but he was unable to resurrect the cells.
Here's Scot's thread: https://budgetlightforum.com/t/-/21182#node-24504, interesting reading...
I, uh, won’t be keeping it stock after all. Components are on the way to make a high discharge cell essential.
Couldn’t help myself. 
Hey Tom, I know you said you put an R100 on top of the R056 cause it’s what you had. What do you think a second R056 would yield? 28 instead of 31 should get it up there pretty good, and the 2 PF’s should handle the load, yes?
Sounds like a Smoke Test.
I got mine on Monday, I’m really liking it so far. I’m planning on doing a review, but the things that stand out to me:
Pros
-Very nice finish, best finish I have and similar to Nitecore MT2C
-Heavy pill area, lots of aluminum
-O-rings everywhere they should be and double rings at the tailcap, will test waterproof by the freeze-and-dunk method
-Super throw (but I am comparing it to my L2T so naturally I am blown away)
-Great design (personal opinion), really like the look of it
Cons
-PWM is still noticeable to me, would like to see this in the 17kHz range like the Qlite driver
-Spring travel and battery tube is too short to accommodate protected cells
-Some threads felt gritty or sharp, may need a polish to get them smooth
Ahh, forgot the #'s - think posted much earlier? Think I got 5.5A to the LED, maybe 4A tail. It's a great host/body for going super high and testing til the emitter blinks out 
. Do realize there's a good step down of effective amps from the cells to the amps delivered to the LED, same I saw in a TN31. Of course in super high amps, 3 cells is better than 2, but the PF's should handle it, but also KP 3400's should too. I don't think lower resistance cells have much advantage in series, as long as the cell can output the amps you need. If the PF's did the amps more efficiently, then longer runtime, but the 3400 have an advantage over 2900's also, so trade-off's.
Yeah you basically talked me into PD’s even more there haha.
I cant go around recommending to my hunting buddies a certain configuration, and then High not working after 60% run time.
Thats exactly why I said for the layman - 3400 protected is perfect. At 4 amps you will be in the almost 2 hour runtime area. For high performance and runtime tradeoff, you cant beat a PD at the moment. 20R’s having 33% less runtime is a tough sell, and I can get almost 6 amps per cell off a PD anyway.
I want to run my big lights at the max end - 8 amps for an xml2, (maybe 300k+ lux) otherwise I’ll just build a c8 with 6 amps and carry 2 batteries (about 140k+ Lux).
Im all about the efficiency really, lux vs weight. If I’m gonna carry a torch 2-3000 vertical meters in a week, and i’ve spent $800 on getting a sleeping bag 300 grams lighter, I’m not going to carry a 400 gram heavier torch for the same use, if you know what I mean.
Chris
Except for one thing Chris, the PF DOES beat the PD, and to prove it, Panasonic replaced the PD in the lineup with the PF. I’m told the PD won’t be available anymore.
Ah well, PFs for me!
Chris
Second package arrived Amanda
Chris
Series. Yes green protected NCR18650B cells from either FT, or mostly WB.
I would not trust a circuit that could have seen insane temperature, or could possibly haven been dropped on the floor or something. When it comes to electronics there will always be stuff that fails with normal use too.
As for the example with Scott, its obvious the cells have been abused due to excessive heat and seen temperatures above whats healthy.
Considering that protected green Panasonic probably outsell KP and various other brands by 1000/1 (guesstimate), its about 1000 times more likely you will hear about an issue involving those cells.
Until anything is proven with good consistency, we are both just speculating about the durability/quality. No doubt the KP use a better protection in terms of resistance though..
With my light (different light with different driver) pushing around 6,4A, im seeing around 4A at the tail. That means about 45 minutes runtime on high. Probably more like 40minutes since amps will raise when voltage gets lower. I prefer to not drain my batteries to 100% or below 3v. Having some sort of warning is nice IMO. If I were a hunter, I would much rather get a warning 5-10 minutes before the batteries are pretty much empty, and then be able to switch to medium and continue what I was doing with good light output. Id prefer that over suddenly have the light shut off due to the protection circuit. I hate having to worry about a light suddenly shutting off. But thats me..
How high mode works on the Maxtoch driver when modified depends on how much "headroom" the driver needs in input voltage vs emitter voltage. It may not be similar to the driver Im using...
If you modify it for extreme amps, PD/PF cells may have better capacity due to less voltage sag, which will be "converted to amps". So in a light modified to the extreme, yes there is a chance you could get slighly better runtime with PD cells. At least if you run it on high all the time. But like I said, I even prefer regular NCR18650B in my light running 6,4A due to the "battery warning" on high. Most of the people who modify XM-L throwers seems to stop at 5A if not a bit higher. NCR18650B do just fine in a series cell light like that. So I wouldnt say Protected NCR18650B are just for the layman.
If the stock driver can do 8 amps or you find the limits too it, please report here
When you kill the emitter at 8 amps. Please report here 0:)
What driver/emitter/battery combo are you using in the 6amp C8 btw?
Driver? No time for drivers at 6amps!
Its direct drive, about 25mm of 20 gauge silicon wires in the whole light, connecting emitter to battery to switch
Ive got a whole thread on here about my c8 endeavours
Ive got a few lights here running over 9 amps. Im over 10 amps on one set up too. Yeah I fry a few emitters, but mostly xpg2. Cant recall ever frying an XML or XML2 at any current, its normally a de dome failure that gets me.
Get your point entirely. I agree going right to the bottom of the capacity isn’t the best idea. LV warning at 3.5 volts just seems a little high to me, 3.0v would be great then staying on low from there. Oh, and most lights don’t go low enough either.
All of my builds I sell have a LV cut off then switch to low. Cant remember what the voltage is but might check that actually. I really like the nangj drivers from fasttech, I tend to keep them below 4.5 amps incase someone gets hold of it eventually that doesnt know what it is and uses a bad cell.
Got the 20Q’s set up in the sn6x-x2 ready for testing tonite, but now my multimeter is flat!
Off to the shop after dinner!
Chris