Not sure if anyone has answered this, but the size of the stove coal, (bigger) doesn't pack in the pot so tightly, allowing more air to flow thru, meaning a hotter fire. But will also burn out quicker. Good for restarting a fresh pot of fuel, or on extremely cold days, (and nights). Nut coal packs in tighter, will burn longer, and can be kept at a lower temp. longer. Good for shoulder months, or oats that don't require as much heat. My 111 will burn a bag of coal a day, whether it's warm or cold out, when my dampers are set the same. But in the late winter, as things begin to thaw, I can set my stove down low, (with nut coal) and it'll burn less coal longer. With stove size, it won't run as long, or low. At least that's how my stove operates. Love the way stove burns in mine, and is chugging away now.
Just caught your thread, and congrats on a perfect stove. Also congrats to Doug for another antique sale.

(Wonder if he still has that 270 Stewart Oak....
