So, we've now uncovered the first big design difference between the "standard" 23" and the HiCap 21" - the shape of the charcoal basket.
While I use the side-by-side split 90% of the time, it's nice to be able to do "front-to-back" on occasion. Given the airflow profile inside the KK, there is a difference in how each cooks, in my opinion, as I've not actually measured temperatures to see if my theory is correct. My impression is that there is practically no difference in left fire vs right fire in a side-to-side basket split, but there is a difference in a back fire vs front fire in a front-to-back basket split, with the back fire being hotter than the front fire arrangement (for the same draft door/top hat setting). This is based upon the shape of the lid. There is left/right symmetry, but not front/back symmetry.
Maybe Dennis has studied this and can tell us if this is actually the case??