Originally Posted by
cyccommute
One of the advantages of battery systems you are missing is portability.
On the other hand, someone might not bother with choosing from any of their bikes for night riding. I can see getting by with two bikes for my night riding (or even just one). I don't need to go clunking through the woods in the dark on my mountain bike, and although I've done some short night rides with my road bike, they're just not necessary.
Gimme a dynohub and running out of battery isn't even a worry.