You smoke a Boston butt in 7-8 hours? How is the tenderness? Does it fall apart when you pull it? My experience with large cuts of meat cooked quickly is they are tough and/or rubbery (there is probably a better culinary term for "rubbery" but I don't know it!). But I have never quick cooked a Boston butt...it may be different.
My normal routine for a 7-ish lb butt is to smoke it for about 6 hours at 240 degrees, wrap it, and put it in the oven at 200 degrees for another 8 hours or so until it reaches 190-195. In all, the cook is around 14-15 hours.
Most definitely fall apart and juicy, never rubbery. I cook mine at around 275-300 wrap when they are around 160 internal, then till 195. I don't have the patience to cook one 14 hours. We cooked whole hogs in less than 14 hrs.