I can confirm this suspicious binning
I tested one of the E2-3C and one E4-3C I bought from MTN last week
Stock D4-1A Emitter 464kcd
E4-3C 489kcd +5%
E2-3C 538kcd +16%
The last one might be a lucky one that is well within E2 binning
Thanks for all the work again, this will be a good reference for building lights with the XHP35!
The question is why is Cree hiding the highest bins in their documentation? And another question: why is Cree not selling them to authorized Cree resellers, like Mouser?
I don’t think that this is made out of no reason.
Earlier the same things happened with other LEDs, like XP-L or XP-G2 (in the meanwhile the bin S4 / S5 are officially documented).
Possibly because Cree was not expecting to produce their highest quality in big enough amounts. Mouser is buying thousands of LEDs in one order and usually they do not stock all tints (or even different bins). If Cree can only deliver a few hundred of one bin Mouser may not be interested to list such a ‘special’ item.
If the yield is constant the new bin will show up in the next revision of the datasheet.
One question: how do you calculate your sweet spot?
Hey, thanks for the question - because the values are completely wrong, and I didn’t even noticed that after six times complete reading…
It’s fixed now. 
Currently I does not calculate anything for the sweet spot, in general I call the point ‘sweet spot’ which is roughly 15 - 35 percent under the possible maximum light flux because such a difference is not really visible with the eyes.
Could be a thing for my upcoming tests to always get the same calculation.
Luminance of XHP35 HI E2 added in OP.
Cheers 
Important notice:
I updated the luminance values for all LEDs shown in test chart including XHP35 HI C4 / E2. I used another E2 sample for luminance testing due to destroying the sample used for first light flux / luminance test.
To ensure more realistic values for 'real-life' conditions (flashlight use / secondary optics) I established a new testing method to determine the luminance with a SMO reflector. All upcoming and already existing tests will use this method!
Updating of my other tests will be done in the next hours / days.
Koef3, so you were getting 2850 lumen at 25°C temps? Did you do short pulses to measure this?
If you were to measure the temps after 30 seconds, where do think it would drop to? Would it hit 85°C temps in 30 seconds?
My cooling rig is very big and the thermal resistance of it is very, very low especially since I optimized the whole cooling for lowest thermal resistance. So I got almost no drop in light flux due to higher Tj / Tsp.
After 30 seconds the light flux at highest current possible hasn't changed in a significant way (+- 0.5 percent maybe). This means also I have not to measure the light flux in short 'pulses'. However, in flashlights (especially these with less massive material in the head) it is almost impossible to get these really good values from my lab testing conditions. But this depends really on flashlight type and board used.
Are we at the point where we can have 2700 Lumen out the front flashlights from the factory?
No, not really. From my experience flashlights have never the same low thermal resistance from LED to case so the highest current possible is lower than in my tests.
I think real 2200 to 2400 (OTF) lumens out of XHP35 HI are the maximum in a mass-production standard factory flashlight. All above may shorten the lifespan of LED and/or electronics significantly...
I have just recognized that my Nitecore MH23 with an XHP35 HD shows a little less brighter spot or dark area right in the center of the big white spot. It can only be seen when doing a whitewall shot but it’s definitely visible. I checked the flashlight’s LED but all four die areas seem to work fine. The dark area only disappears when being closer than 1,5m to the wall. Any distance beyond 1,5m will reveal that there is a minor dark spot within the spot.
According to the first post of koef3 I assume this is absolutely normal, isn’t it? Unfortunately I cannot post any pictures of the whitewall shot as the camera sensor will immediately equalize the light intensity to the aperture.
That can also be from the reflector not being at the perfect distance from the die.
Found same issue with Nitecore light, seems the focus of the reflector is not optimal
Thank you Enderman & Lexel! Is there anything I can do about it or would you recommend to accept this “as is”? I must admit I have not recognized it when using the MH23 outside.
Just to rule out any own faults:
Can this dislocation between emitter and reflector happen when the flashlight suffers small shocks from falling (during transportation) or is that very unlike to happen? I’m talking about veeeery small shocks, so 4-6cm of drop height. 
The only way to fix it would be to open the head, which I’ve heard is pretty hard on most flashlights from nitecore.
If you don’t notice it much during use, don’t bother.
The reflectors are very solid inside the light, and the thing that would cause a donut hole is a Z axis translation, so no it almost certainly isn’t from any drops.
Alright, thanks a lot! So, I don’t need to be worried about it. The dark spot can only be seen if you really look for it on the ceiling or wall. My MH23 only “dropped” 4-5cm from a bag into a plastic box while inside its holster. So, I guess this does not even count as a real drop. 
Raw data
Cree XHP35 HI C4
Amps lm Vf
0,20 354 11,72
0,40 623 12,22
0,60 890 12,62
0,80 1113 12,92
1,00 1311 13,17
1,20 1493 13,39
1,40 1686 13,61
1,60 1851 13,83
1,80 2000 14,02
2,00 2124 14,20
2,20 2240 14,38
2,40 2339 14,56
2,60 2413 14,75
2,80 2463 14,94
3,00 2496 15,14
3,20 2496 15,37
3,40 2463 15,51
Cree XHP35 HI E2
Amps lm Vf
0,20 360 11,47
0,40 707 12,03
0,60 976 12,42
0,80 1246 12,74
1,00 1487 13,03
1,20 1702 13,27
1,40 1909 13,49
1,60 2091 13,70
1,80 2273 13,91
2,00 2421 14,11
2,20 2545 14,29
2,40 2645 14,48
2,60 2727 14,67
2,80 2785 14,86
3,00 2826 15,08
3,20 2851 15,29
3,40 2843 15,52
If you create diagrams / comparisons with this data, I would ask you to publish these charts in this topic and also to specify the source of the data used. 