Until Jack answers, my thoughts.
Finish temp will depend on the meat itself, that's why I only use the temp as a guide. And instead of cutting it open like Jack, that's where I use the poke/prod method.
Put a probe in the part of the brisket that will have the best slices. Usually in the middle or towards the outer thirds, but it depends on the thickness and uniformity.
Cook a flat to about 160 to 170 and wrap in foil, if that's your preference. Add just a little juice (add something with flavor, but not more than 1/4 cup or it will stew in the juice and fat)
Take the brisket out at 195 and see what you think. You can do Jack's method if you prefer to check, I just think it will start losing juices when you slice and reheat.
Take the juices/juice that was in the foil and separate the good stuff from the fat (get one of the fat strainer pitcher things)
TaktEZ.
You know, experimentation is half the fun. I'm not sure it's worth the extra money, but HEY, it's only money. The problem will be that it will cook different than the others, usually a little faster. Some people only cook the Prime or the Kobe. I say try it, have some fun.