the Kelly kettle for getting hot water fast from just about anything that would burn is the only wood fired stove i can see that has any use.
The kelly kettle is an expensive, heavy, single purpose overrated gimmick
with moving parts
You can equal or surpass it with a hobo stove, a regular pot and metal pot skirt (heavy foil + 3 screws to maintain 10mm gap)
The outside of the pot alone offers double the surface area than the internal chimney of the kettle , provided you use the skirt, and you don't lose any of the functionality of a pot, and its about 8 times cheaper
Add an improved stove (woodgas...) and the kettle can't compete