This method works great on rib roast or chuck roast also. Really hard to mess it up. Don't have to worry about having a stall or drying out the meat. You're more likely to cook the meat too soft and mushy if you leave it on the dutch oven too long. For pork butt, i prefer to have some texture so typically 4 hrs in the dutch oven gets me to a 200-205F internal temperature. I've done it for 6 hrs but the meat loses texture and gets too soft/mushy for my taste. Also if you prefer more bark on the meat, just smoke it at a higher temperature between 265-275F. For very large size of meat, just cut it in half to speed up smoking/cooking time. Another thing is that if you're using a cast iron dutch oven, make sure it has been preheated to 225-275F when you place the meat. Lining the bottom of the dutch oven with herbs/spices/aromatics is optional. Sometimes i only use whole black pepper.