I have a new elite also. My first butt 8.5 lbs took 21 hours because I cooked it at 200 while I was asleep then bumped up to 225*. Just pulled my second butt at 11:30 (16.5 hrs) this morning, I started it at 1900 last night. I injected in with vinegar, water, sugar, salt, and pepper and used CS Rib Rub. It was cooked at 225*, I didn't touch anything until the meat reached 195*, then I removed meat, FTC, and added a half cup of apple juice warmed to room temperature. Now I am waiting for supper time.
I have never checked the oven probe, but once the oven reaches my temperature setting, the indication on the control panel has never varied more than two degrees from my set temperature.
Hope this helps!!!!