I noticed in the "before" pictures, there is, what appears to be drippings, as if you had "parboiled" or pre cooked the brisket a bit? You also said it was kinda "chewy". The final product looks great, I was only wandering if there was a "hidden step" that you didn't mention. I have never tried to "precook" any of my briskets and was also thinking that may be the reason it was "chewy" was because it was "semi-precooked".
Don't get me wrong, the final product looks YUMMY! I'm only curious.