Received my Z2 the other day, and i love it. It is really sad to see nice little lights like this not get more love here. $17 shipped for an XP-G2, watrerproof, well built. Ah well, i guess some secrets are best kept secret..
In terms of use.. it has replaced my TK15 for EDC. Yes, it is less bright. Yes, it has less run time. But it is lighter, easier to carry, and has a common battery should it be needed. The OP reflector produces a very nice soft spot, but still achieves moderate throw (no, you wont be white wall hunting 200m away, but you will have no problem navigating a building in a power outage, or working on a vehicle on an unpleasant night. And while not worth much, it is neat that the ring sealing the lens from the body is a glow in the dark, and glows pretty well after the light was on.
In terms of durability.. the pocket clip is sturdy enough, and the anno looks good (we will see on that). It passed my dunk test (no problems being left submerged while on.. no water ingress at all). The button can take a little getting used to, but works well.
For negatives, the lower levels are PWM, which can be noticeable. I don't mind it too much, but can't lie and not say its there. Additionally, if you listen close, you can hear a buzz. Again, nothing huge, people it can be noticed. To a degree i wish the high pushed the emitter a bit stronger (~200lm), but i know that is for battery life more than anything...
All in all, i have spent far more in far worse ways. I really can't complain..