I wonder if Nitecore made a point of hand selecting an example for you to test, for the best beam pattern possible. While the beam pattern on mine has a hotspot that has definition similar to what yours shows as, I do see a rather prominent greenish ring around the perimeter of the hotspot zone. It's not really a concern when putting the light to use on non-white objects, but you can't help but notice it on a white wall. I'm just wondering if that ring got washed out in your photos, or if there are emitter variances in the production run. I've seen similar hotspot tint rings on other lights like the Olight M20, but the Surefire U2 and NovaTac 120P have extremely clean beams in comparison, at all levels.
I also agree that the lower beam should be down at least 50% less than what it is. There are 4 brightness levels, evenly spaced out in intensity, and it feels like I wouldn't bother with the mid level. I could see having 3 of those levels, with the 4th much lower as a kind of moonlight mode.