No, U only get excess creosote if U back the damper down too much. U should periodically run the stove wide open (when it is cold out) to reduce it. I also cleaned the flue myself every year.
The Sotz kit was air tight, and designed so the stove could not get hot enough to burn itself out. Also, in the basement, the floor was concrete. Still use one up at my hunting cabin, have NEVER HAD A PROBLEM WITH THEM. They put out a tremendous amount of heat, and are very efficient. They will also accommodate some pretty long pieces of wood. The most efficient wood stove shape would be a sphere, next a cylinder (or barrel), a rectangular stove is not an efficient shape.
When they were tested against the best wood stoves of the time, they put out more total BTUs, and more BTUs per cord of wood burned. After that, the Gov put them out of business!