In terms of weight, a saw beats a hatchet any time, for most applications. However, in terms of collecting firewood, there is an even more efficient solution - bare hands.

I have built a lot of wood fires over the years, some in emergency situations and some not, and I have never had a problem collecting enough wood barehanded. Long branches are shortened by stomping (stout boots help!). Dry pine needles, twigs, and small stuff are readily available on standing trees. No tools at all are required.

I have never understood the incessant discussions on batoning which strikes me as a completely unnecessary procedure and a good way to abuse a knife.

In recent years, I have built fewer and fewer fires. Small efficient stoves are safer and quicker and there are lots of options available.

Montanero's remarks emphasize that you must not only have a gadget, but also have the knowledge and experience to use said gadget safely and effectively. Build lots of fires before your life depends on it....