I've got a rocket stove, and I'm familiar with their operation. But not as a mass heater. I've read your page.

I've already purchased, planned (with the city) and will have installed a Pyro 4, which is very efficient and low smoke and uses some of the same principles as a rocket stove, but isn't quite a rocket stove as there is a door and there is no feed chute. The main chamber is a ceramic tube normally used in kilns. It pulls air from under the door and burns towards the back of the tube where the exhaust goes up, back over the top, then loops back around to the flue.