I've had a few NexTorch lights. I still have the K1 and K3.
The K3 is nice. Good, creamy-white R5 emitter, OP reflector. The lumens mentioned seem very accurate. Mode order is: 180 lumens on high, 75 on medium, 25 on low, then a 180-lumen 9 Hz strobe. Leave the light on for five seconds or more and it will come on in that mode next time you turn it on. It comes with two NexTorch-branded alkalines in the light so you can "Try Me" as well as two new ones in the package. The clicky is nice and I didn't think I'd like the metallic finish at first, but it's just fine. Although there's no texturing on the light, it doesn't really need it, as it doesn't slip out of my hand when in use. The pocket clip spins freely and isn't removable without cutting it.
The head unscrews for battery change, although there is a seam near the tailcap. I marred my K3 up pretty nicely trying to get the tail unscrewed with pliers, so they must use Locktite or something on the threads there. Overall, it's nice: on par with the Preon 2, and costs less money.
EDIT: The clip is removable. On the wire clip, there's a small piece of flat metal that says NexTorch. It will slide up to "lock" the clip on the light, or down to allow you to pull the springy clip off the light.