Insert with convection mantle?

[rickj]

First winter season in the new house, being unimpressed with the 20 year-old simple insert, 70x45 cm with a blower. Looking more and more interestedly at the inserts I mentioned here: https://www.hearth.com/talk/threads/stove-interior-vermiculite-versus-steel.205528/post-2744421 (Metalfire "Optimum")

These do not have a blower, but expect you to install the insert in an enclosure, channeling cold air from the room around the insert, through its heat-exchanger, and out back into the room through vents on top (see drawing below). So the air moves up, around the insert, by convection, taking in cold air at the bottom of the device, expelling it quite near the ceiling.

I'd like to hear experiences with a setup like this. The old insert blows hot air at a height less than 1 meter, at sort of sofa-level, while these convection inserts expel their hot air far higher up in the room, quite near the ceiling. Does this work for you? Did you add a fan for circulating warm air in the room?

The 3rd pic below shows the living room; it's quite elongated, with the fireplace at one end, in red. So I worry a bit that the other end stays cold.