I love mine. Light it using the menion method, set the vents correctly, and it will keep a constant temp for over 20 hours without loading more fuel. You can sleep through the entire night and not have to worry about getting up to check your temp. If it weren't for the BBQ Guru that I bought for my big Green egg, I'd never smoke on anything else. They have such a following that it has a web forum dedicated to it (Google Virtual Weber Bullet).
By the way, if you buy one, I'd buy the 18.5 inch version. The smaller one is way too small for a brisket, and the largest one will use 3X the fuel while not having as precise temp control. The 18.5 inch version, in my opinion gives the best of both worlds. That's also the most popular version by far, and thus it will have the most help online to help you master it, which goes a long way towards you wanting to continue to use it.