I think the use of USDA Select briskets by restaurants is one of the little secrets that many DIY barbecuers don't know. We automatically assume that higher grades of brisket are better because higher grades of steaks are better, and we've heard stories about barbecue competitors seeking out USDA Prime briskets for that "edge" in contests. But many great BBQ joints use USDA Select...just knowing that Select is good enough for John Mueller says a lot.
I also found it interesting how the temps vary from Pitmaster to Pitmaster. I've been looking more and more at your high heat cook: http://virtualweberbullet.com/brisket4.html