My feeling is that this may be a good product for someone who wants to keep it stashed in a vehicle for immediate use while traveling, but $300 is a lot of money. Unless you need the collapsible factor, you could build one just as good for a few bucks and a couple of hours with hand tools. If you want the function while traveling light, you would be better served by learning to make a Dakota pit stove.
The unit looks to be sturdy stainless steel, and the hinge seams which would be slightly leaky are probably tight
enough for the purpose. Many of the claims of superiority are not valid against typical rocket stoves; I am not sure exactly what they are comparing it to for these claims. I think it would operate exactly as well as any other rocket stove built to good dimensions. If used for serious cooking for a long time, the metal would probably start to warp if not corrode. Based on the promotional text, there will be no real user reviews as it has not been produced in commercial quantities yet.