Have Brinyte B158, want the next step up, 1x26650.
Jaxman z1
Cometa
Any others?
Did I read somewhere that the Cometa had poor quality glass limiting it’s output? (aside from its other qualities, like the pipe bomb thing…)
What kind of kcd is capable by either of them?
Between those? Z1
You can expect quality from Jaxman.
Or get 2x B158 for the same money. 
I have about 15 B158 and B158B at the moment, I’m good.
I’m really in the mood for a 26650 zoomie. Is the Jaxman Z1 the go-to light in that category? It seems that way…
Well, it depends on what do you want this light to do.
Uniquefire UF-1504 will be throwier than Z1, but is said to be of worse quality.
The Z1 ist generally the highest quality one. It has a good quality lens (no lottery…) which is even ar-coated.
But…
The lens has a long focal length, so you loose a lot of light when foccused, the hotspot is rather small and you have to turn the head quite a bit to de-/focus it. It also makes the light very long when focussed. The other annoying thing is the loose threads of the head. When de-focussed slightly touching the light will change the focus a bit.