As a Chef a couple things I would like to touch on. Cook no higher than 275 because it gets hard for the heat to sink in slowly, keep up the humidity in the cooking unit by water pans and don't let them run dry, don't let the meat sit for any time with the rub on before cooking, don't trim, don't remove fat cap, don't brine because it will say on package salt added and it means its already done for you, try to buy bone in when you have the chance because the meat will have less surface area and bones add good things, dont be to fast to pull it apart when it's hot let it rest.
At the Ironwood I use a cookshack brand smoker and can fire about 100# at a time, I use my standard rib rub and inject apple juice concentrate and apple cider vinegar in a 3/1 ratio, I'll put the smoke (hickory and apple) to them hard for first 3 hours then open spritz and run them for 3 more hours, the smoker will shut down, I'll spritz with injection liquor again close up and wait until I remove them a couple hours after when I get a free minute.
IMHO from cooking tonnes of pork butt boned out and bone in although I buy both, bone in is better by far because it pulls into better, longer strings of meat and has more flavor. I pull by hand with heat resistant gloves which allows me to keep long strands while removing the remaining unwanted fat and glands.
Well as you can see Uga, BBQ is not rocket science, but a hodge podge of ideas. I always apply rub the night before and place the butt in a plastic bag, in the fridge over night. Then when we pull it out in the morning, add more rub to the meat. Rub=Flavor. I will add that water in the pan does add moisture, but not much. It is there as a heat sink and to provent temperature spikes. I have actually used play box sand in place of water and see no difference in the final product. With the humidity we have here in Florida, you really don't need water when it is above 80% humidity. Moisten Playbox sand does the same thing but allows for more consistent and higher smoker temps, especially when using Charcoal. Definitely agree with the bone in.....it adds more flavor to the meat and helps the meat cook quicker.
With all these differences, you have some practicing to do.
Never seem more learned than the people you are with. Wear your learning like a pocket watch and keep it hidden. Do not pull it out to count the hours, but give the time when you are asked. --- Lord Chesterfield
Interesting comments but I believe simpler is better. Where I grew up there must be 50 barbecue joints within 25 miles of town and nearly all good. Most cook small boneless butts over open pits fired by oak. Most will cook around six hours moving the meat around on the grill from hotter to cooler areas as needed. Of course this method requires the cook to pay close attention while cooking. None cook to pulled pork doneness but serve it sliced or chopped.
Nearly all cook the butts with no rub but let the natural goodness of the pork and oak cooking shine through.