Interesting looking though not too sure how ergonomic that arrangement is. Fenix is certainly willing to be adventurous as far as experimenting with very different looking lights. This one almost looks like a pair of roof prism binoculars.
I like it! (not going to buy it though)
Nice to see a (/more) compact and pocket friendly side by side reflector lights with good output.
This light is pretty cool. There are 2 independent battery compartment and you can use 1 or 2 18650. For example, you can use 1 of the LED with 1 18650 (2x CR123) or both LED if using 2 18650 (4x CR123).
Can someone give me a good reason I would not prefer to have two separate lights? Assuming same output and beam profile etc.
I could see this on my quad
Reminds me of one of those old rectangular TV remotes that you had to hold with 2 hands in order to press a button firmly enough. 
So what you are saying is that it is two independent lights which share one control switch? Interesting. Sounds like it could also be used to store valuables or non conductive items in one battery compartment and still be a useable light.
Hmmm… There is only one button for the two lights and a little better heat dissipation. 0:)
Its way more convenient/practical/easy to operate one switch compared to two.
Its way easier to hold one light compared to two (in the same hand). Most people would not use two lights in one hand or find that practical.
Its way easier to get one light to light up one area compared to having two lights pointing in exactly the same spot.
The way I see it, is that the light is less bulky (thick) compared to a typical larger single reflector light with good output, and its also got better output compared to all single XM-L2 lights on the market, so it needs to be compared with more powerful lights (multiple XM-L2`s or MT-G2)
Most multiple XM-L2 lights are usually triple emitter lights that are larger. MT-G2 needs a larger head.
Fenix own TK35 UE (1800 lumen MT-G2 light) is a nice rival, but LD50 is way more pocket friendly, and it will actually outthrow TK35 UE. Sure, the TK35 UE have its advantages as well, but what other stock lights can offer similar output, great build quality, nice features, great runtime in such a thin and compact package?
Yup, it is also useful if you don’t have enough battery in a emergency where you can just use one of the LED.
Too bad it’s expensive.
Most of the three or four batteries in parallel soup can lights have the same capability for running with fewer batteries as long as you do not try running on the higher output levels. My RMM modified Supfire M6 and SRK clones are putting out 4600 to 5000 Lumens at initial turn-on per RMMs sphere readings and I suspect that your average single 18650 would not appreciate such attempted current draw. In fact the tests were done with Sony VTC4 high current capability batteries.
Zippy ties are cheap. 
i kinda like this too. so im assuming the belt holster would look something like for the smart phones . hahah
them smart phones are gettin huge these days.
If you build it, they will come.
Sorry… I know I’m going to get flamed for this but I think it’s darned UGLY 
Nah, not really hard on the battery. Since it's direct drive, the current that will go thru the LEDs is determined by the voltage, and one cell instead of 4 will sag more, and more voltage sag means less current. It's self-limiting.
If it were a boost driver where it would try to draw whatever was required to reach the proper output current, and that input current could only be safely supplied by 4 cells in parallel, then trying to run it on 1 cell would be bad. But a direct drive setup will never act like that.