225 is what I use. Some people on the forum will go 235, but I would never do that for a brisket. 210 sounds very interesting to me, and I think I will try that on my next brisket, but since this is your first brisket, I would go 225. The timing/schedule that was recommended for the cook was based on that. As I mentioned earlier, there's nothing worse than a brisket that has not had enough time to cook and rest. Error on the side of being done early, with a longer rest. Since you trimmed 3 pounds of fat, you might want to recalculate your time, and start at 5pm the day before.