@SmallFront, I'm glad to see someone else here with this light. Is anyone here in the US using it?

@PaulRivers, you've done a good job at laying out the tradeoffs of various different technologies! As I said in the beginning, it would be nice to have a user-replaceable Li-Ion battery in a bike light, but I haven't seen or heard of one. Possible reasons (that I'm just guessing): 1. manufacturers don't trust to handle the cells safely, 2. cells aren't readily available anyway so there's not much point, 3. cell quality can't be assured. Any others?

And ease of charging does seem to be at the expense of ease of replacement. I know it sounds petty, but opening the device, removing the battery, inserting it in the charger, waiting, taking it out of the charger, replacing it in the device, is a bit of an annoyance or hindrance. It's nicer for me to plug the device in without disassembling it. As I said, I already charge a bunch of USB devices, so this is just one more. My "charging station" is already pretty cluttered.