nitro organized a group buy thing - nitro posted above. Not sure, but he may have more left. I wish I ordered more now 
, but 16 mm's would be great, but the 16's are not stock items at SinkPAD, the 20's were. Possible plan is to put another group buy together for 16's (or 14's), but include payment for the tooling costs to SinkPAD, so it will cost more but the more we buy, the less % is the tooling cost.
Thermal compound/paste is only good for bridging vewwy vewwy tiny gaps, such as microscopic irregularities in surface finish, down to the scale where you can't see any roughness with the naked eye. If you have a divot or pocket or wide gap, skip the paste, it won't do anything but make a huge mess later on when you take it apart again. Heat just doesn't transfer thru a big glob of paste.
I know a lot of you guys just like tweaking things for the sake of tweaking, but the fancy expensive exotic compounds aren't doing anything but lightening your wallets... just pick up a giant tube of white silicone-based paste from the electronics store. It'll last you thirty-seven forevers, and performance, when used correctly, will be within the margin of error for whatever equipment you're measuring with. Changes in ambient temp during the test will show more variation than between the most expensive and cheapest stuff.
Similarly, for filling gaps or pockets so you can correctly use thermal paste, or for permanently mounting stuff, plain ol' JB Weld is just as good as Arctic Alumina or any of the other fancy ones. And like the white thermal paste, you can get it in giant tubes that last forever ('Industro-Weld' - exact same JB Weld, just in bigger tubes). Skip the JB Quik - it's not as strong or as good at heat transfer. If you're curious, squirt out some of the black JB, and poke at it with a magnet... (hint: it's got lots and lots of metal in it, but it's not electrically conductive).
Interesting, comfychair. I’ve used superglue to bond stars to a heatsink before. apply a small amount, press with a lot of weight for about 10 seconds, and it’s on. I was surprised to see the star only be 4-5 degrees hotter than the heatsink. Worked quite well, and it’s temporary since the glue will not bond good to smooth aluminum. I would not use it in a real application unless in a pinch, Shock or lateral pressure seems to jar them loose sometimes.
I either use Fujik (probably a fancy name for overpriced silicone sealer) or thermal paste when I have something to hold the star down.
Has nothing to do with driver efficiency, I promise. They’re both linear drivers (AMC7135 Based) which means that tail current = emitter current.
PPtk
i see, do you know anything about voltage drops, as i am looking to order a driver very soon and would like the one with the least drop
If you’re wanting to stay with a Linear driver, then any AMC7135 based driver will have VERY similar voltage drop. If you are looking for switching buck, then they’re all going to be vastly different in how much overhead they need in order to maintain regulation. You’d have to ask the vendors.
PPtk
Thanx comfychair - I hear what you are say'n, but I'm trying to stay away from the epoxys, just using grease as much as possible. I got a few small tubes of the Arctic MX-2 for like $1 each, and am only using tiny dabs now. As long as I can get the two critical surfaces (bottom of star and top of pill where it mounts) as even as possible and very smooth with 2000-2500 grit paper, nothing much more is needed, from what I understand. I thought thermal grease is still better than air (according to heat xfer specs) so still think filling larger gaps is better than nothing. Just following others advice, measurments, tests, published data mostly - don't have instruments or the setup to measure these issues. I read all sorts of issues/opinions/facts on this subject here and on CPF, and believe me, it's a tough call. When someone tested toothpaste to be as effective as the top shelf stuff, I was stunned to say the least - but that's true only in thin applications, thicker applications the higher grade thermal greases/epoxies proved to be better from what I recall. However you view it, I'd rather take my chances with better stuff that seems to have been shown to be more effective in some circumstances. For example, you can test toothpaste when fresh, but what about after 3 hours of high temp use? Even for a $7 tube that lasts through 70 mods, that's only 10 cents per mod - I can live with that. Oh, even if I use epoxy now, I'll use it partially so the parts are easier to get apart later, the rest is grease. I'm trying to stay as thin as possible - general consensus I've been hearing.
Bort - it’s important to remember a couple things about the binning. Cree states +–7% error in flux measurements used to bin them. That’s basically ± 1 bin in error if you are just looking at the average difference between the bins. Statistically the bins are just chunk of what is likely a normal distribution (I once saw a graph released showing old Luxeon bins that was normal). That means the top bin is always in the tail of that distribution. The bin below may or may not include the peak of the distribution. Bottom line is it’s likely that the expected difference between the top bin and the bin just below is less than the average difference of 7%. The measurement error is then bigger than the expected difference.
Bottom Line - Everything else equal, the top bin is likely, but not necessarily, brighter than the one just below it.
The XinTD is next! Going to 3.8A with XM-L2 U2 on a SinkPAD. Started it, removed the U3 (ouch) - hoping to complete this evening. The SinkPAD doesn't quite fit, again, so will sand it down a bit, not as much as for the HD2010. I already got 2 copper discs in the pill, so it should help.
Wow! I am watching this one closely Tom. C8 size lights are my favorites ( except for my A60 ) and this one is going to be a monster.
mostly good advice - but a pocket of air isn’t helping either, so why not fill the gap with something, if you’re not paying too much for it ;)…
also, jb weld isn’t a good conductor - but it isn’t a very good insulator…afterall, it has all that metal in it. be careful how you use it, w/ respect to electricity, ie don’t pot drivers with it. I love JB weld - I’ve used at least at least 100 oz of the stuff - I buy the 2x5oz jb weld off ebay.
I'm hoping on over 1200 because the XinTD is in the 900's now at 3.5A and a U3.
JB isn't conductive, I've used it on very sensitive low voltage stuff like bare motherboard & video card traces, and high voltage/current stuff as well. I guess if the voltage is high enough just about anything will turn into a conductor, but not an issue with things that won't kill you dead. I've even used it for potting, of a sort, for USB thumbdrives that had cheap flimsy housings... stripped them down naked, gooped on the JB, then sanded down after cured. They worked fine.
It's a good thermal conductor, and good electrical insulator. Now if those were reversed, then it'd be about the worst thing possible to use.
i think capacitance is more of an issue than conductivity. because you succeeded at encapsulating electronics with epoxy/powdered steel doesn’t mean it is a good idea - do you think I’m speculating? or do you think I found out the hard way lol 
back to the OP
Tom, the numbers look great, but what are your eyes telling you?
Unfortunatly, haven't had much time to play or use it outdoors, so hard to tell. The little I did, it does appear to be the real thing. Of course lots of opinions whether you can see 20% or so difference, but the meters don't lie. Really need to get in some open spaces to see these things throw. I don't have any good setup for outdoor beamshots so that's difficult, but I do have a stock HD2010 to compare with.
Can’t wait to see this.
Prelim results on the XinTD XM-L2 U2 on SinkPAD is so-so. can't seem to get the full amps of 3.85A, best I can get is 3.57A on a fresh Pana 3400. On a fresh Pana 2900, get 3.47A. Weird. With the Pana3400, lumens readings are 1142 @start to 1101 @30 secs. Definitely dissapointed there, but it may be the seating of the SinkPAD. Was getting a lot of upward pressure from the teflon silver tinned 22 gauge wires on the SinkPAD because of the tight squeeze - pushing limits all around. I know the independent driver test measured exactly 3.85A as it should when done on a mounted T6 for test purposes.
So, thinking I don't have a good bond for the star, so I can enlarge the pass-thru holes/edges of the star to eliminate some or all pressure, and maybe add epoxy in the center to secure it down well. Still can't explain the low amp measurements though... However, I've seen some strange lower amp readings on these XM-L2's that I couldn't explain also... Maybe there is an issue there with over-driving them.
If the emitter is resisting current somehow, the Vf has to go up or VIn has to drop (Ohm’s law prevails). I doubt the LED is jumping it’s Vf suddenly based on current or heat, since heat usually makes Vf drop slightly.
I’d look at the switch spring and if there is a driver spring. Those steel springs add a lot of resistance to the path. I’m not familiar with this particular light, so I’m just throwing out the areas I usually look at first.
Dang, Tom, that’s an awesome upgrade, mate 
Good job! 
Looking at the datasheets, it appears the XM-L2 may operate at a slightly higher forward voltage than the original XM-L. Anecdotes from P60 builders on CPF apparently supports this—their direct drive XM-L2 dropins apparently draw lower current than a DD XM-L. That withstanding, I find it hard to believe that its Vf is so high that 12*AMC7135 cannot regulate current from a freshly charged 18650.