I happen to like more of a smoke flavor on my pork butt than what 2 hours will give. I usually smoke my butts for 4 - 5 hours, then finish in a slow oven for another 4 hours. Heavenly!
My boss only smokes pork butt for 2 hours, nor does he cook it long enough to make it "pull". We run it on the slicer, cold, for sandwiches, portion it out, then heat portions to order for the sandwich. IMHO, the meat is a pale comparison to what I make at home, which pulls easily with two forks.