The inventor of that is a poster here and had one of his axes going around as a "test" ax. I believe the impression of it was that it worked good on soft wood for shelling off the small pieces like they show in the video but was just about pointless for quartering oak or the like. The cost is about $200-250. In europe, they burn wood differently than we do. We use large pieces and try to get a long burn by controlling the air supply.
In Europe, they use small pieces and let them burn as fast as they want to heat the stone or masonry and that radiates the heat after the fast hot fire is gone.
Ian