That all looked really good!
To me, your brisket looks like a trimmed-up chunk of a part of the brisket that we call the "flat".
I'm working on making better briskets myself. So far, the ones that I made also got a little dry. I'm finding Brisket to be one of the more challenging meats to smoke. Next time I cook a flat, I'm going to try the "high-heat" version and foil it for a while, in order to keep it juicy. (You might want to try the same.)
Long times like 10-12 hours or more are usually for "full packer" briskets - which is a BIG pice of meat consisting of a full "flat" and the "point", with a pretty hefty fat cap. (these are probably about 8-10 Kg).
Keep experimenting - I'm going to do the same.