I made one. I can tell you there is much more to it than a can with holes.
It burns the wood and then the gases in the smoke can be re-ignited and burned as fuel. This second burn is a clean smokeless burn.
For auto or trailer camping this is a lot of work and not entirely smokeless. There is a lot of smoke and sut when getting it going, or when the fire gets low, or too high. The fire needs to be just right to work perfectly, which is most of the time, but not all the time. It is for outside use only.
For short camp trips in a vehicle/camper propane is quicker and cleaner.
For long stays or the true off-gridder this stove is the ticket.
Your pots will become black.
There are battery powered models out there that blow air into the fire to feed more oxygen that burn hotter, quicker too, and probably give a more consistent heat.
This has nothing to do with a fire ring, or truck wheels or any kind of fire pit. Im not sure why people are talking about fire pits in a stove discussion, but such is a forum...