Far more useful than you'd expect.
I bought this product as a replacement for standard mess tins, along with the Genuine 58 Patter Bottle and mug. I keep these three items together (mug on the top of the bottle, bottle slides into aluminium cup) when I am in the field, as they provide an excellent source to cook rations, with water, and then take a hot brew after. I was dubious about this product, but it balances perfectly on top of a normal gas stove, and boils water incredibly quickly. I am significantly more satisfied with these three items which all go into one pouch than I was with standard mess tins, and would advise anyone to use this set up, even perhaps over a jet boil. Just be careful when using the metal handles after boiling water inside!
CDT SGT Miller, 1349 Woking, Surrey Wing Nijmegen