Just this week I had 2 butts that went for ever. 2 7 lbs that just wouldn't go over 193 degrees. After 20 hours I decided to take em off foiled and rested for 2 hours then pulled, they were great. These are the first ones I ever trimmed the fat cap off before cooking, and put them on the cooker fat side down. Don't know if that had anything to do with the long cook time. Other than the cook time I didn't notice much difference by trimming and cooking fat side down.