I have cooked both flats and whoe packers in my MES, both have turned out great. Flats fit in great, packers, I just bend a little and they do touch the sides but havent had a bad one yet. I never go by time just internal temp. I always wrap @ 140, salt and course ground black pepper rub then let her go till 170 or so for slicing. ( never pulled brisket but have read 190 for pulling) Cooking temp @ 200.
I have had a problem with not getting a smoke ring even though plenty of TBS, great hickory taste just no ring to speak of. I saw another post on here saying to use 1 peice of charcoal in with wood chips and it will solve that problem, havent tried it yet but have tried using Morton's tender quick and produces ring every time, may be cheating, but I got good flavor and my ring.
Good luck with the brisket and look forward to the QView.
Nice demonstration site. Not only does it show how to trim correctly, it shows visually the difference between a flat and a point. Yes, I'm a newbie . Up to this point I had never split them before smoking them on my ECB and while them came out very good, I was always wondering the best way to slice them. Now I know!