I don't like to have to speak ill of a small manufacturer having a go, but if they've been making stoves since the early 1980s how much product development have they done since then?
I've been heating mostly with wood for twenty plus years and have had fireplaces and woodstoves in the home going back to childhood so have some interest in the subject.
I suppose if smoke output is not an issue and fuel is free but for the work of collecting and handling it, and one wants the fastest possible heat output after a fire is lit, then perhaps a case can be made that a simple steel box will begin to transmit heat to the room slightly quicker, but personally I doubt it. I heat with a large double door insert with large windows, so I can see what is going on as long as I keep the glass clean.
In any stove, get a decent fire going with dry wood and then put on a damp piece and what happens? The whole fire "sags" or even goes out as its reservoir of heat is absorbed by the cold, damp piece of wood past the point where it can maintain the other fuel at high enough temperatures to combust. Of course it all depends on the relative sizes of the fire and therefore its thermal reservoir and the size of the green or damp piece put on. Forest fires as we can all see have such enormous thermal energy that they can burn even green wood and keep on going; it's all a matter of scale. The comparatively feeble heat output of damp wood in a stove or fireplace compared to dry is something most of us have probably noticed: the energy is going into evaporating the moisture from the wood, not into heating the room.
So, a stove body which transmits heat outwards more quickly to the room might make you a little warmer a little sooner, but what are the combustion temperatures as a result of that rapid transmission and relative inability to hold heat in the combustion area in the way that a lined firebox does? How complete is the combustion? How much of the combustible gas is being burned and converted to usable heat and how much is simply going up the flue and being lost? Combustion of the gasses typically only occurs with a baffle and secondary, usually pre-heated, air inlet; the famous so called "secondary combustion [chamber]".
There are a given number of BTU's in a piece of wood, depending IIRC mostly on it's weight and therefore density, the resin and moisture content. Secondary combustion stoves are more efficient; they get more BTU's into the room for a given weight of wood all else being equal.
One only has to see the roiling flames of good secondary combustion and feel the heat given off to see the difference. More heat from the same quantity of wood easily outweighs the purported speed of transmission of heat through a metal-only stove.
A proper fan which moves air over the stove back/top/sides is a must have IMHO and I put in a manual override switch on my insert so I don't have to wait for the thermostat to turn the fan on, but once it is on, if I turn the switch to off the thermostat will then shut down the fan once temperatures drop low enough. A handy feature when going to bed and wanting the noise of the fan to stop when the fire goes down.
Firebrick certainly does hold heat once hot, as does soapstone for example, though I find the soapstone stoves take too long to transmit heat because their entire bodies are blocks of soapstone with no substantial metal surfaces and sometimes not much glass for rapid heat transmission. The masonry heater was in part designed to provide a day's heat from a relatively short burn time once or twice a day, and thus a more efficient use of fuel which was much more accessible/cheap in some areas than others. Maybe the soapstone stoves have a similar potential; I believe that is claimed at times.
Speaking of heat transmission, the amount of heat passing through the glass "windows" is much higher than through steel. If I stand a piece of firewood outside the doors in front of the glass of my insert it will rapidly scorch in a way that it never does when just laid on top of the 1/4" steel firebox for a final drying. And that final drying and heating of course minimizes the heat lost in the firebox when a new piece of wood is added as the wood is already dry and quite warm and uses less of the residual energy of the existing fire to bring it up to combustion temps.
I've gone back and forth a bit there, but you get thes idea I'm sure.
A few moments casual looking online produced this for example:
https://salamanderstoves.com/product-category/the-hobbit-stove/
https://salamanderstoves.com/product-category/accessories/stove-extras/
https://salamanderstoves.com/about-us/
The enamelled stoves produced mostly in France are quite something though the styles are not everyone's taste.
And so to bed!
