Well, I'm certainly no expert on brisket. In fact I've only done one, but it came out so good that I am going to do another in a few days. What I did with mine was smoke it at 250 until it reached about 165, then I put it in a roasting pan with some beef broth and some dry onion soup mix. Covered the pan with heavy duty foil and put it back in until it got to 200. Then it went into the cooler (pan and all). Since it got done way ahead of when I thought it would, it was in the cooler for about 5 hrs. When it came out of the cooler it was very tender and not dripping juice but it wasn't dry at all. Looked like this:
Now, I don't know if the secret was that it was in the cooler so long or what, but I'm going to try it the same way again and see if I get the same results.