I just wanted to confirm these findings, though I did not test as rigorously.
I swapped in a KD supposed XML2 U2 20mm star emitter into a meritline C8, drive current ~2A.
I have a LM C12 with an XML2 also at ~2A and it is noticeably brighter.
This is using the same battery even.
very good information here, and a good heads up . thanks for your hard work tom!
Interesting, thanx for the info!! Boy, if we could only get KD to respond to a direct question on this, giving them the true facts.
Just another data point, I just got an xintd XML2 U2 C8 clone and it is just as bright as the LM XML2, drive current also appears to be ~2 amps. This confirms the KD emitter as odd one out still.
So what does KD have to say about the fact that they are selling Fake Emitters ?
Thanks for the tests, the results confirm what I was fearing already: a lot of chinese vendors use different bins than claimed.
Although the way you measured appear to give consistent results within the same supplier, for a permanent bin-test set-up (that I want you to start using for all of us 
) it could pay-off to reflow the leds on the same type of board everytime (say: a Noctigon), and just mount the board on a large heatsink and measure the lumens (lux) without a flashlight, using the same (lineair) driver board everytime. That excludes quite some uncertainties.
Agree - just didn't have the setup and or/time for that. Relic, Match, and others do a much better job. I'm not planning on doing this much in the future, but, I definitely will be much more selective with vendors. I sent a support post to KD yesterday about this mis-labeling - no response yet. If they do respond, will probably be useless. I don't want to be harsh because could just be their vendor and they don't have the capability to verify.
Hank at IOS in a pm told me other vendors do false claims on these emitters - he was definitely proven right. He's my most trustworthy HK source...
KD responded - they sent pics of their CREE wrappers. I though it was a joke - the CREE label # is this: XMLBWT-0-1B0-U20-00-0001, dated 01-Jun-2013, So the chromaticity group (tint) is 1B, but of course they don't sell 1B's, only 1A's. Hhhmmm... I replied and questioned that -- see what they reply with now, if they reply....
I’m surprised they did reply with a photo of the reel.
Will be looking forward to their reply as well. 
Let me guess Tom E showed them that others (stores) show a photo of a reel?
With the advent of Photoshop and how easy it is to manipulate a photo, I don’t think anything but a video of unboxing the LED’s with their store name would be credible. We’ll see…