I just did four butts this weekend (again) and I'm still new at this. Mine took 17 hours. I had planned for between 15 and 20. If it had taken twenty, pulling would have been painful (we had a pulling party and I handed out food service gloves to three others and taught them this fine art). For those keeping score, I used sand this time and will never go back to water.
Dinner was scheduled for 6:00pm with ~40 people. The weekend went like this:
Friday evening: Slathered and added a modified Mr. Brown (no mustard powder and ran short of a couple things, improvised a couple others). Packed all four in 1 gallon freezer bags and set in the refrigerator until Saturday night. This was no small feat. We were camping and the refrigerator in my RV is pretty small. So is the counter space to work with all the meat.
Saturday evening: 8:30pm, fired up the grill using the Minion method. When the temp approached 200 degrees, I dropped in all four butts. There wasn't enough room. I was concerned because the meat ended up pressed together. I just decided to "go for it". I spent about the next hour fiddling with lower air vents to try and get it "perfect". Eventually I got bored with trying to get it perfect and went back to the party.
Sunday Morning: The temp held rock steady at 229-231 all night until about 7:00am when I woke up. It had drifted down to 210 or so. I opened the door, stirred the coals a little bit added some more just to make me more comfortable. I also added a couple chunks more smoke meat (I was using Oak and Apple). I played around with the vents a little more just for fun and then got bored again.
10:00am Sunday: I had been so good, but I had to peek. It's a weakness. I called over some other members of the group that had expressed an interest, and we had a brief ceremony. Gawd, they were beautiful!
1:00pm Sunday: The largest of the butts reached 192, and I pulled them all off, wrapped them in foil, and let them rest in an ice chest set aside for just this purpose (a warm ice chest). Then, I went sailing.
Winds were great and dinner was postponed until 7:00pm.
6:30pm: We had our little "pulling party". Each participant had their own turkey roasting pan. When they were done pulling, we covered each pan and returned them to the chest to await dinner.
They were beautiful. This WSM just keeps getting better and better. The best compliment of the weekend came from a member of our fleet. He is a VEGETARIAN! He had seconds for lunch today.
It was a winner.!
Relax, have some fun and try not to worry. It will be a thing of beauty.
Chet