Well said Gary.
Nice post! Just one addition...1 to 1.5 hours per pound is typically valid for smoker temps between 250 and 300°F. At 225° to 250°F it is much more common that the average sized, 8-10lb, store bought, vac-packed butt, will take 2 hours per pound. At any temp it is a good idea to add 2 hours to your estimate to cover the unforeseen. It is always better to be done early and hold the butt, up to 5 hours, wrapped in towels and in a cooler, than have hungry guests staring you down waiting on the meat...JJ