My only experience with brisket is costco prime and GFS. I cooked a choice GFS yesterday and the flat was really dry. I am not sure it is was my method or lack of fat. I cut it super thin and will use for samiches.
flavor was good but I think I am going to stick to costco.
Odd part of the cook was, it was about a 14 lbs brisket and cooked in like 8 hours.