Over here also achieves improvements between 8% to 10% in kcds in my mods with AR multilayer glass lens regarding original lenses without any treatment 
if you don’t mind me asking, what mods did you do to your Intimidator to get those levels of kcd? and what model was it? ( SR90, 92, 96, etc.
Thx for the informative follow ups. I have a feeling that the differences netted measured as lumens in my PVC LMD will be lower than measuring throw. Will do a beam throw comparo in the future and remember to include measurements without glass at all.
Again this was just a sample size of one so would be interesting to test additional samples in the future. Looks like a visit to flashlightlens.com is in my future. 
I would also like to know 
Well, the most annoying thing about AR coated glass lens is that the light gets kinda green tint after emitter dedoming, especialy if the emitter is 5700k and under
I had my Javelot default emitter replaced for that reason
Even without dedoming the LED.
That’s why I don’t like AR Coated lenses. I buy 4C or 3B XM-Ls because of the good tint - and then a lens destroys it 
Not for me… I preferably have a bit less lumens but a nice light color than the other way around.
Why not buy a LED that tends more toward red (something with “A” or “D” tint) for use in lights that use AR coated lenses? If you really don’t like the green tint, why are you buying green tinted emitters? 
The A and D are more towards pink than red, but I would ask the same anyway. Most B and C have green tendencies at their core due to their Y axis placement. The easier way to expose that green it is to compare side by side with something equivalent from A or D, whoever the famous "dual tint" of the CREE XM-L LEDs can be more or less visible based on the shape and size of the reflector.
De-domed XM-L2 U2 1A and modified driver. The driver makes too many amps for the XM-L, so I removed their “sense resistor” and stacked resistors to get 6.6A to the emitter. *Olight used a bar, like in a DMM, for resistance.
I put a UCL or UCLp in every light that I favor. The UCL glass lens in a MiniMag Light really disappears, well, ok, it does that in most all of em. Without reflections from external light sources the emitter and reflector look really awesome when viewing the light.
I haven’t bought other AR lenses, can’t say I know what y’all are referring to about the green cast…haven’t noticed that in any of mine but I HAVE replaced Olight and other brand name AR lenses that had a yellow tint to the glass. Lay it on white typing paper. Can you see it? You have to be careful where you put down an UCL lens as it’ll get lost very easily!
The green cast thing is an interesting observation. not something i’ve noticed myself with the Ucl lenses.
But it makes sense in theory since the coating’s purple/bluish cast would indicate it is still reflecting those colours to some extent while letting the green/yellow/red through almost completely unhindered?
Correct, when you look at coatings and see a particular color, that's the wavelength that the coating is "canceling" out. AR coatings have no color, here's a great article on the topic:
http://rick_oleson.tripod.com/index-166.html
I should also add that in my testing, I was trying to see the differences in tint with and without the coating (purple) and couldn't find anything discernible. This wasn't merely just observing it with my eyes but I videotaped it and then compared still frames. However, I believe a coating aimed at green wavelengths would have made a difference.
This would explain my dislike of the tint in the nw blf X6. I've been wondering why the color seems really pale and greenish.
As an experiment, try shining the light around with the lens removed…see if it still gives that greenish cast you’re not liking. Curious to see if it makes any difference.
I just tried it. The AR lens of the BLF X6 does indeed cause the beam to look greener than without. Now I wonder why there haven't been flashlight AR lenses that look green instead of the typical blue/purple/pink (at least I haven't seen any). It might make for a more pleasant overall tint.
Edit: I'm curious if the stock non-AR lens changes the color at all. Unfortunately, I don't have one to test.
Read Turbo’s link
TL;DR
Single layer AR coatings target the middle of the visible light spectrum (green). This gives the highest light transmission throughout the visible light spectrum. But it causes slightly more transmission of the center target (green) then the rest. It also gives the lens a purple-ish reflection off the surface.
There isn’t anything they can do about it with single layer AR. Try an led tint that has less green to begin with. UCL lenses are advertised multilayer and supported by people saying it doesn’t have any green tint.
I'm guilty of not always reading everything before posting, so thanks for the clarification. I've gone over turboBB's link and think I kind of understand it now. I incorrectly assumed they could simply target the greenish blue or red part of the spectrum with a single-layer AR coating, but it appears that would negate the purpose of the coating in the first place, as it wouldn't affect enough of the visible part of the spectrum.
It seems like UCL is the way to go. I'll be picking up some UCLp's for my "better" builds and sticking with uncoated lenses for the rest. Even if the single-layer AR lenses do increase output, the shift toward green simply isn't worth it for me. It's actually the primary reason I haven't been using the BLF X6 much. An emitter swap does seem tempting, but I'm hesitant to mod the light after all the work that various members put into it.
Edit: Terminology.
locusto03, look at it like this… when you order food at a restaurant a chef has gone to a great deal of trouble to prepare your meal, correct? Then when you get it at the table, you add salt and pepper to taste, do you not? Modifying the X6 would be like adding salt to that dish, tweaking it to your taste.
Read Turbo’s link
TL;DR
+1
That is a good way to put it. I'd actually use it more, rather than having it sit in the box. 
The AR coating will not significantly increase output. These coatings are to decrease reflection and may increase or decrease transition, but only slightly. The only case where one is useful is to decrease ringyness in a light with otherwise a very clean beam. I think they are used to make the light resemble other optics rather than for any usefulness.