Received tonight. These are really impressive. Build quality is top-notch-- just a really solid-feeling light. Also, smaller than I thought it was going to be. Anodizing and finish feel excellent. A specific detail I really appreciate is how the tailcap edges are nicely chamfered and filleted; this makes sense given how much time your fingers spend on the tailcap, but it's a detail I haven't seen elsewhere. The O-rings are nice and beefy and came well-lubed. I like the ingenuity of how the reflector is threaded into the head but also into the body. It lends the head a stable, solid feel if focus adjustments were needed for different bulb types.
I used 2x Efest 700 mAh 18350 with the FM1794 bulb. WoW! These are put out a ton of great quality light. I even brought the cells down to 4.05V before using them, and the color temperature is really nice.
Since it's an incand, it seems like >80% of the light is in one giant hotspot, making it seem perceptibly brighter than it really is. Shame we can't get any more of this type of light once they're gone.