+1 for the who cares about the "golden" 24 inches.
There is no scientific reason behind this from what I can tell. It seemed to work for one person and everyone else took it as gospel. The truth is if you can maintain the right temp at the grate you're good.
18.5" WSM (Model #2820)
Used Lang 48 or Meadow Creek TS60 or Klose being hunted for so if you know of any PM me