Just an update - over the course of about 4.5 hours the internal temp dropped from 185* all the way to 175*. It stayed at 175* for about 30 minutes then began to slowly climb. Back at 185* I inserted a probe with still a little more resistance than I'd like so I let it go to 191* before the probe entered more easily, so I wrapped in foil to rest at that point.
This was by far my best brisket ever. Sliced very easily and was very juicy. I am totally sold on the UDS for long cooks. Managed the full 11.5 hour cook with only a 9 pound bag of RO briquettes and 5 wood chunks. Only had to make 3 slight adjustments to the vents over the course of the cook.
I know, no pictures - it didn't happen. Unfortunately, my daughter borrowed my camera and forgot to bring it back when she came to eat.
Large Big Green Egg
Weber 22.5" One Touch Gold