This is a super lightweight headlamp that I will probably use on most of my backpacking trips. While it might not be quite powerful enough for night time off-trail hiking, it will be more than adequate for just about everything else. I really like the high CRI LED - it is brighter than that from the Nitecore NU25 which makes it very usable around camp.

This headlight is very lightweight. I like the CRI option while still having the Cool White LED. The modes of 28 LU and 130 LU are well spaced. The low of 1 LU is too low to be useful. The CRI is stated to be 50 LU. I found this accurate. While using the main LED light, the beam pattern has a defined hotspot, with decent spill light. The tint is CW, but not overly so. The CRI beam has a nice beam that is even throughout. It is much light a floodlight. It has limited throw, but there are instances where a high CRI with an even beam can be more useful than a beam with a tight hotspot. The low mode on the red light is too low in my opinion as well. The higher mode is better for map reading and such. The flashing of the red LEDs are good for signaling. The flashing red mode is done in its higher level.

The adjustable headband is long enough to fit any size head. I can see it fitting around caps and helmets too. There is a thin strip on the inside of the band that feels like silicon. This helps in keeping the strap from sliding down your head. Although the light is very lightweight, I would have liked to have the second strap that also goes over the head for better security. There are three areas of the headband that have reflective markings. They are a nice touch, but I would have liked to have seen even more than just three areas because depending on how long or short the headband is adjusted, one of the three areas could be covered in the overlapping of the headband at the adjustment point.

The tilting of the headlight offers four positions. I found if you are using the main LED in either the highest or medium mode, and you are in one of the two positions that aim the headlight down lowest, you will be able to see spill light from the LED. The glare is bothersome. It feels like a flashlight is being pointed down on your face from directly above your head. This does not occur with the CRI LEDs or red modes though.

I did a runtime test in CRI mode. The stated runtime was 4 hours. I got closer to 2 hours of 50 LU and then it slowly lessened over the next two hours to about 5 LU. The amount of light was still useful, but for only close-up work. The battery power indicator is useful. It blinks 3X to show there is over 50% power left, 2X to show there is less than 50% and one time to show there is less than 10% left. When there is less than 10% left, the NU17 no longer has a high mode, only low, med and med. All other functions still work, such as the SOS/Strobe and the red modes, just not as bright.