I ended up cooking 2 more briskets using the same exact process, another 10lb and a 7.5lb. The 7.5 came out much better than the 10lb. I think the larger brisket leaves too much of a possibility for temperatures not being consistent throughout, thus creating pieces that are chewier than others.
I used beef broth instead of beer. I don't think this made a difference, but I did use more broth this time, almost 2 full cups.
One other thing I did with the cooks was after letting it rest for 45 minutes or so in the foil I sliced the brisket and put it into an oven safe baking dish. I used all the leftover jus/gravy and mixed it with about 1/2 a bottle of Rufus Teague BBQ sauce. I'm a firm believer in this BBQ sauce, available at most high end grocery stores in Texas, as it contains no High Fructose Corn Syrup, and it does not use any ingredients you cannot pronounce. I pour this mix over the brisket and cover the baking dish with foil. I let it soak in the oven at 175 and much of this gets absorbed into the brisket. It comes out AMAZING!