I ordered the AK-16 from KaiDomain, just received it. I liked the idea of being able to use 14500, AA, and CR123 primaries all in the same light with only a 1mm diameter increase over the K-106. Putting a battery in it is a bit annoying though, as there is a spring in both the tailcap and the head - I had assumed, and would have preferred, a slightly longer AA shim and spring in the tailcap rather than having a shim and spring both front and back.
The switch in mine wasn't grounding the best, allowing a very slight flicker. I took out the switch and pushed out the ground contact more so that there'd be better contact with the tailcap body. Seems ok at this point.
Anyway, I had a couple of questions for owners of the K-106/AK16/etc.
1. How long does your light need to be off for it to retain the current output setting in 'memory'? Memory works on my AK-16, however the light needs to be off for about 8 seconds, if you turn it back on more quickly it will forward to the next output mode. It's a little annoying compared to my other lights which seem to set the 'memory' setting after just a couple of seconds. I saw one comment relating to memory, but I'd be interested in what other people have timed their lights at in terms of setting the 'memory' mode.
2. Has anyone been able to judge the approximate efficiency of this circuit, or at least had a good head-to-head test with another light with known efficiency charts? I am, like many others are, big on efficient circuits. Progammability is great, though being relatively efficient is at least as important for most. It seems to perform well from what I can tell, though I would be interested in any actual tests.