CyclingSalmon14, the thing is, I don't really want to have to think about all those things. It seems to me that it would have been such a simple thing. You have two batteries, and you have two LEDs. Why not have one battery run each LED, in parallel, similar to the ZL S6330? That way you wouldn't have to think about having to match cells, or even have cells of the same age or mA rating. It would just be a non issue.
Anyway, after seeing some on-line videos of the beam pattern of the BC30, I went ahead and ordered the B&M Ixon Premium. I think the Fenix light will be great for folks who ride trails, etc and needs lots of power, but for my needs (mostly riding around town and a bike path), I think the Ixon Premium's unique reflector, which gives a hard horizontal cutoff, will give me a much more bike trail and roadway friendly beam.