I must be one of the few mini builders that have stayed away from building a charcoal ring. I just don't see the purpose. For longer cooks, I want to be able to load as much fuel as I can possibly cram into the bottom of my smoker. To me, the charcoal ring reduces the amount of space I can fill with precious fuel. They look really cool, but again, IMO, it reduces the amount of charcoal I can load into my mini.
Tim