Try trimming your meat raw to about 7 inches wide so when cooked it will fit nicely in the box. This is preferable to trimming the brisket after it's done; having a "natural" uncut end on your slices will help your appearance scores.
I agree on too much sauce. Also watch your drips and try for as much general neatness and symmetry in the box as you can.
I would say 6 or 7 depending on if it looked overly sauced it person from farther away I bet the box looks better. I also don't really care for the look with the burnt ends in both the front and back.