I would have rated 3.5 but rounded down to 3 because it doesn't score a 4 yet but with some slight modification it could score 4 or 5.
First the compactness and weight make it great for storing in a camper van, caravan or car. The box it comes in will be adequate for storage & lifespan can be increased if you wrap the box with gaffer tape.
Now for the flaws:
the main flaw is that there are no vent holes in either n the sides or the base, I suggest drilling three or four quarter inch holes in each side and maybe a few in the base - my reason for suggesting this is that due to the depth of the box/pit itself it creates a smoke vortex which causes smoke to go in all directions and change direction everytime you try to avoid sitting in its path - this occurs even with a constant wind direction; when there is a fairly strong wind, a light breeze or no wind and the use of a wind break makes matter worse
the other minor flaw which may not be solve able as i am not a metal worker i don't know, is the slight bowing out of the panel after use which seems to increase slightly on each use - we have used ours 6 or 7 times now
Overall I am happy and love the concept - if the manufacturers can improve the smoke problem & possibly the distortion problem then this has the makings of an excellent product.
I intend to experiment by drilling a few holes in mine - will report back here with the results.