I use a couple of different methods to determine if meat is done. If it is bone in, then bone wiggle is the best way, hands down. I start to check when the pull back on the bone is apparent. I do not use internal temperature very often, but, 190F is where I would start.
If boneless, then I use a pull test, I will grab a part of the butt, just a pinch and pull it, if it comes easy, then the meat is ready to come out of the pit. Another way is to feel for softness, if the meat feels soft, then you are probably done, if there is resistance when you squeeze it, then it needs more cooking.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"I'm Armenian...perhaps...but then again...maybe not..."