Got mine today, full gift set - really, really nice so far - love the tint. I was soooo disappointed with the S1, and I bought two, one is still unopened in the box. The blue tint of the S1 is ridiculous, plus locked in un-replaceable LED.
Of course I'm not crazy about the UI with the pres&hold. Seems almost broken that a single click from OFF does nothing. Much rather have the ramping UI of Narsil, or the mode sets, plus the power. Now the fun begins - seeing if it I can get full access to the driver and get a ATtiny85 based driver in there.
The tint looks absolutely perfect to me - no shading around the hot spot, just a nice milky white, slight hint of yellow. I dunno where you can buy a U2 5C - makes you wonder how legit it is. I only see "5X" tints in a T5 bin at best (MtnE has a listed T6 5C1, but limited). I'll drop in a fully charge 16340 IMR and measure it up - see what the real turbo level is.
Also it seems to throw decently for it's size, much better than the S1.
I think I'll xfer the LED to a Noctigon at first - well worth keeping it. The stock MCPCB appears to be regular aluminum.