Looks awesome, if I had to guess I would say it was that brisket in particular with more fat than normal, not so much the grade.
It appears to have more fatty sections than I am use to seeing.......
What was the final temp readings on it???
I only ask as I am going to start attempting to keep the temp readings closer to the sub 200 for the next few times.
Somewhere between the 195 and 200 is what I am considering...............
I would like to think it can be as tender and more moist by doing this.....including the extended rest of course.