OK, I just read your original post. Doing brisket for Christmas? Then I would recommend test smoking a brisket and taking notes: weight, smoker temp, rubs, etc. If it turns out well, repeat. If not so well, adjust. Butt and brisket are two different animals (no pun intended) but if brisket is for dinner, then I would do the test run with brisket. Disclaimer: I have never done brisket. I am a pork fanatic. Good luck.