I just see no reason cutting flavor off the piece of meat till it is finished cooking. I do not believe in the self basting theory, but I do believe it is flavor imparted during the cook. I believe it does cook into the meat, and it comes off like cutting Jell-O when it is done. Very easy to deal with after the cook. I am also not a big rub guy and certainly do not like bark, 2 major reasons to trim very close. This is only seasoned on the top.
As far as the 300° cook, it is somewhat necessity today. I had to have this ready by 5, so it could not be cooked low. I also adhere to the theory that as much smoke flavor is being delivered at 300° as is going on the meat at 150°. This is about 4 1/2 hours in.
The flat is over 190° and the Point is still around 175. The color is where I like it, so I am gonna separate it, foil it and put a probe in both sections and still hope they are done by 5. I would like to rest it for at least 30 minutes! Will try and flip it over and show the thick fat!
A couple of questions because I am still working on making brisket work:
You did not trim. It looks like there is a fat cap on the bottom. What advantage do you see in leaving the fat cap untrimmed (provided that is what you are doing)?
What do you see as the advantage of cooking at 300 degrees?