Good advice here all around. I have a Large BGE and I do not spritz. I generally use olive or vegetable oil first, then put my rub on. I have put mustard on just before putting on for smoke, I seem to get slightly better bark, or at least bark in the style I prefer that way.
The stall will TERRIFY you the first time around, it will sit in that 160-170 range for hours and may even back itself up and you will obsess. It's OK, it's normal.. and it's normal even knowing that to still freak out!!! If you're not getting the probe tender/internal temps and you're getting pressed for time you can wrap them in foil with some apple juice, apple cider vinegar and that will help move them along. It will soften up your bark but it will help you power through the stall if you're short on time.
BTW make sure you're getting 225 on the GRATE(in an indirect spot above the plate setter or whatever you're using) and not the dome. The dome may run a bit hotter and you may not have enough heat on the grate if you swear by that dome thermo.
Give yourself TONS of time. They need to rest for at least an hour after they come off the cooker so if they're ready 2 hours or so before it's eatin' time better that than late. Wrap 'em in foil and a towel, bury them in a cooler. I actually have set my oven to 150 and put them in wrapped in foil, turning the oven off after an hour. Long as you don't open the door they make great "coolers."
Good luck and enjoy!
Large Big Green Egg, 18.5" WSM, Weber Genesis Silver