Thanks for the feedback, all good points. One reason I was considering the Fenix as a tail-light is that it would be easier to mount on my bike than a DiNotte. I can't figure out how to mount a DiNotte on my bike since I use a large Carradice Barley seatbag that makes my seatpost unusable for that purpose. Looks like I'll stick with my PB Superflash for the time being.