The two videos start a list but the first video in each is what you want to see. First off these are not rocket mass heaters. They are rocket stoves and a rocket stove fired oven. I have looked at brick/cob ovens for some time, but they use a lot of wood and time to get hot. Unless you are running a bakery they are a once in a while deal. I have also seen the barrel oven which is a white oven, but bigger than any cabin I want to build needs. It is easily twice as big as what I would use day to day.... though it might be handy for once a year dinners with lots of people over. More wood used than needed the rest of the year.
The oven shown in the video in the url above is much smaller, heats very fast, and seems quite controllable. They were able to run it at normal oven temperatures as well as kiln temperatures. However, what really caught my eye was the second video where they combine the oven with two more rocket stoves to make a kitchen. The unique (to me anyway) thing is that each "hob" and the oven has it's own fire hole. This means that each pot and the oven can be controlled separately rather than having one fire box running the whole show.
The oven is a black oven, but the rocket heater for it is very clean and there appears to be very little ash showing up in/on the food. They have no flue but then neither do gas/propane stoves and ovens. As with any gas appliance there does have to be proper ventilation though. I wonder if a hood with a flue would vent enough or if another rocket in the flue path would act as a fan. A shutoff would be needed for when the kitchen was not in use either way.