This is something awesome I found and recently built, and it has actually replaced my charcoal BBQ for high temperature cooking. I've found it gets more than hot enough to sear steak golden brown with my cast iron skillet.

Some things I altered about the design were:

• I fired two whole tube shaped bricks and one C-shaped brick, the idea being that a cylinder will focus heat better and prevent pockets of higher temperature air from forming. Also, gaps in the bricks used in the original design likely reduce the insulating properties of the sawdust.
• Fired one additional wafer shaped brick with a lower sawdust amount (25 g Sawdust for every 115 g clay) and left a gap in the cement base so I could let the waste material out into a bin. I'm guessing that at a certain temperature the sawdust will compromise the structure of the brick, and I expected the bottom to get really hot. It seems that the ash provides adequate insulation anyway.
• It looks like in the video they used dry pine. The wood I have was cut this year (for winter), and likely adversely affects the temperature and therefore the efficiency of the stove. Not to mention it's hard to start.

I haven't built a second, regular one yet to compare it to.