For competition, I cook brisket at 250 in my offset. I foil at 165 with a little beef broth, then start probing about 2 hours later. Unlike pork butt, I believe there is no set temperature for brisket to be done to perfection. I've had the probe slide in like butter at 190 and other times have had to take it to 205. In any case, this method cooks most 15 pound packers in 9 to 10 hours with pretty consistent results.
When I'm not competing, I often cook brisket without foil in the BGE at 210 degrees for 14 -18 hours or even more. I think this method gives you better bark and a more smokey flavor. It's just not predictable enough for competition.
Cooking brisket seems to be a very controversial subject among BBQ cooks, and there are many different opinions about the 'right' and 'wrong' way to do it. The best advice I can give you is to find a method that works for you and your cooker and go with it. Texas crutch or no.
Mister Bob, Pitmaster - Bob's Hogs. KCBS CBJ #31759 - IMBAS Certified MOINK Baller