Cool, I hadn't heard of that model. Typical rocket stoves use the J-tube style, but there also batch boxes that look more like a typical wood stove. Important thing is to burn hot and clean since smoke is wasted fuel, then extract more of the heat from the flue gasses to charge a thermal mass. Sounds like you're on it.
Discussion
Pyro Classics were developed locally in New Zealand, in the Upper Hutt on a government grant, before being released to run as a private company.
At the time there was no incentive for people to lower smoke emissions so the industry didn't make low-emission wood burners. Nobody would even want them. The government wanted to put in regulations, but if they had put them in all existing wood burners would fail. They decided to see what was achievable first instead of trusting industry to tell them. And they got really smart engineers to do it. Consumer Reports rated it as #1 for both efficiency and emissions for many years (a rocket-stove like reburner model has beaten it now, but it's much larger and tricky to operate).