Just bought the white-gold LG G4 Dual-LTE! The "gold" looks like gold as long as you're in good lighting. If not, it looks just like the sides of the regular G4. I like the matte feeling of the back, but the white has made me a little scared that it will dirty easily.
In any case, they included 2 leather backs (pink + blue) -- which are NOT the official LG leather backs. They are VOIA brand. However, on the box of these leather cases, they call it "Original accessory licensed by LG". Design is almost exactly the same as the LG one, except there is no stitching and there is some metallic plastic at the sides (leather doesn't go until the very edge of the back). But texture of leather is exactly the same as the original LG one.
Besides that, they also gave free 128GB microSD card (Class 10 SDXC, also Voia brand) and microSD adapter, 2 plastic screen protectors, and battery charging kit, which I appreciate.
Overall, at M1, this one costs $30 more than a leather G4 (w/ batt charging kit only). At Singtel, same price as regular leather G4. I find this white-gold a better deal than the leather G4 (even though I only use 1 SIM)!
Also interesting is the model number is H818N (same as other dual SIM variants), and software version of this is v10a-SEA-XX, after one update. I think this doesn't follow the update cycle of your H815, but I hope when Marshmallow comes it comes to my phone just as quickly as yours.
If you got any questions just ask!