Got mine today - sure does feel great in the hand. Should be easy to add power with stacked 7135's, but really if you go much higher, it should be upgraded to a DTP MCPCB anyway. The UI isn't bad, but not that great either, compared to higher end lights. Double click on the e-switch turns it OFF, but I find clicking through modes triggers a double-click, and the light goes OFF when you don't want it off. Also, if you are on low mode and want to turn it OFF, you double-click, but the first click displays the next brighter mode, so you get flashed with a brighter mode in order to turn the light OFF. This is why I hate double-clicks on e-switch's, unless you can get the timing 100% perfect.
The tailcap power switch has memory, while the side switch will always start on lowest mode. Modes are from lo to high, double click turns the light OFF when ON, and single click turns it ON to low when OFF. I'm real happy with how they kept the overall length very close to the original X6 - usually the length would be extended when the full tailcap button is retained. The SolarStorm SC02 and Roche/Convoy F6 are two examples of small length e-switch 18650 lights, but both don't have tail switch's, so it saves a lot on length, but they heat up quickly big time with little mass or cooling in the design.
I confirmed with or without a tailcap spring bypass, the light will do 2.8A with a fresh battery. Mine does roughly 1,000 lumens with the claimed U2 3C - nice output, and match's the advertised specs - amazing!
I also got the cheap squashy white box with mine, and I have one small nick on the bezel's edge, probably a direct result of the poor packaging.
I would still prefer my own UI for e-switch's, with a FET+1 driver, but probably would lose the charging ability - will have to look more closely at the driver. It's possible the charging circuitry is totally independent from the MCU, and if so, might be possible to piggyback in one of our drivers and retain the charging capability.