For me an important Apekt was that the three legs can be unscrewed, so that can hang or put the bowl in the garage or in the garden shed to the wall without taking up all too much space.
From the size I feel a diameter of 75cm than ideal. There, firewood can burn easily with a length between 25 and 50cm, without the burning wood falls right out of the bowl when the fire falls apart after a while. With a smaller diameter because I had my doubts.
Although the shell has no holes downwards, the air supply is no problem and the wood - at least if it is sufficiently dry - burns well and evenly, without a lot of lumps of coal are left behind.
A little side note: if the shell - as shown in the picture - used on the lawn, the lawn goes under and around the shell due to the large heat radiation a. Therefore, one should perhaps not position the dish in the middle of manicured rolling lawns, but rather at a location that has a suitable ground or on which one can also cope with the broken grass.