Did my first full packer earlier this year and here is what happened.
Got a 12lber and based on past experiences with just doing flats, I know longer use a regular rub Just salt and pepper 50/50. That bark becomes this nice salty bit of awesomeness, by itself it is salty but when that flat is sliced it is just awesome.
Based on lots of questions asked I smoked it until about 165 and separated the point and the flat which was really easy at that point. I put the flat back in the smoker after adding some more S&P in the area the point was connected and took her to 195. I rested it in a cooler for two hours then sliced her into the best sandwiches I ever had and my father in-law ruined by putting ketchup on it.
When the point was removed from the flat I chopped into one inch cubes, sauced it, sprinkled with rub and put it back in the smoker for another almost two hours with occasional stirring and adding of rub.
I will always do it the same way from now on because I can't ask for anything better in my opinion. My guests were WOWed by the burnt ends and loved the brisket sammies also.
Total smoke time was about 21 hours at 235-245 in my MES using the AMZNPS with a fully tray of Pitmasters choice.