Wish I had a good idea for you to thank you for all the good info. /ubbthreads/images/graemlins/bowdown.gif Only other thoughs: a cyan just to see how much further you could see. A warm white for no paticular reason. They appear to have already implemented a syncronous rectifier so effeciency is already likely good. I'm currently guessing 1.75 W in. Mine draws 300 mA on fresh cells. We don't know the Vf or actual current of the stock Luxeon. In theory would amount to 1.2 W of course. Yes, you could put a Lux III in. Might be a minor color shift from being under driven, but would likely still produce more light. How much? I don't know! I'm still looking at the circuit to see if I can figure out where the current is set. Most likely is R (next to C1) which is labeled R10 (should be 0.10 ohms) but I haven't figured out how.
You would think the modders here would come up with something. /ubbthreads/images/graemlins/poke2.gif