I'm on a team of guys who, for church events, break out my buddy's big trailer smoker that can hold about 20 full size briskets. We had an open house last weekend and while cutting everything up, and dealing with a lot of what seemed to be leftover fat that really didn't melt down, started wondering if we should trim them down before smoking. Trying to describe the cuts we get, there's the main brisket part that you recognize as the rectangular shaped slices, then there is a ribbon of fat, then the top part of the brisket is a mix of fat and some meat. I think we ended up using a fair amount of that top part for chopped, but wanted to see what y'all thought about us trimming that top part off (maybe not all, but most of the fat) so we get more smoke into the full, rectangular part.
A little info on the prep. We pretty much take them out of the package, rub with a "secret recipe" rub, and then start the smoker around 6:30 the night before and run all night to about 6:00 when we stop feeding the fire and let them rest, in the smoker, for another 2 hours or so, then take them out and rest another 1/2 hour before slicing. They are still steaming at this point, and of course we're sampling them along the way.