re: One meat I struggle with smoking is the brisket.

My method, not saying it's right:
I do salt and pepper
Fat down
225 degrees
Around 165-170 I wrap in butcher paper
When it gets to 198 I slice an opening in top butcher paper and start probing the flat and point. When I can poke it with no resistance I pull it.
I have had them done at both 198 all the way to 208.
I usually go with prime but have had great results with CAB Choice.
I let it sit on a counter covered in a towel until internal is 140.
I slice as needed and never slice the whole thing unless it is being eaten at that moment.
I usually cook on a WSM with lump charcoal and have a temperature control device.