Just received mine from Illumn.com and charged up the included battery. The build quality is great and feels good in the hand. It has a unibody design where the head and battery tube is one piece, which allows the entire flashlight body to be used for heat dissipation, which is an excellent design IMO. Also the deep fins in the back of the head are excellent for head shedding. Light looks great too.

However, I don't like the UI. Click to turn on, click to change modes, and click and hold to turn off. If I knew the UI was like this, I would not have bought the light. The single button UI on the Olights, Thrunites, and Acebeams are so much more intuitive and simple. Also I'm surprised Nitecore used Micro USB instead of the much preferred USB-C given how new this light is. Nitecore should offer a 4000K version since head lamps are much more useful and easier on the eyes at warmer temperatures. I'm disappointed in all the manufacturers offering CW only. Even Olight is starting to offer NW emitters like in the popular M2R Pro and Warrior X Pro.

Output measurements taken at 2s after turn-on using Texas Ace Lumen Tube calibrated with Maukka lights. Spectrometer used is the Sekonic C-800-U

Nitecore HC35 Mode 5 2,612 lumens 8271K -0.0088 DUV 71.5 CRI 4.7 R9 45.3 R12 62 Rf 99 Rg included battery
Nitecore HC36 Mode 4 789 lumens 7356K -0.0036 DUV 72.3 CRI -7.6 R9 42.5 R12 66 Rf 97 Rg included battery
Nitecore HC37 Mode 3 253 lumens 7081K -0.0010 DUV 73.1 CRI -11.6 R9 41.3 R12 68 Rf 96 Rg included battery
Nitecore HC38 Mode 2 37 lumens 6836K 0.0010 DUV 73.4 CRI included battery
Nitecore HC39 Mode 1 2 lumens 6541K 0.0022 DUV 74.1 CRI included battery