I used to run 2 FENIX lights - one on the head and one on the bars.
I've since switched to only one on the head, and find that it alone more than suffices. The additive effect of 2 FENIXs aren't so impressive, since they just overlap. In fact, I notice no difference in riding with only one Fenix.
Just wondering if anyone had any experience similar to mine, or encountered situations where the extra handlebar torch was really critical.