Honest thoughts here UTK, on the pit, looks good. Bark developing nicely.
On the cutting board, the flat looks a bit dry and not much smoke ring. I attribute this to you having to ramp up the heat to meet the wife's deadline, so in essence, you baked it rather than smoked it. No biggie. You were under time constraints, so it's completely acceptable. For your first effort, you done good.
Couple of thoughts for your next smoke:
If your wife tells you that there's going to be folks coming over for supper, and she wants it by 6, tell her it'll be ready when it's ready, and stock up on more beer for the guests. They'll wait, I promise. Never had anyone walk out and say "Screw this noise, I ain't waitin' for the brisket to be ready."
Secondly, when you slice it, slice it across the grain, which is not necessarily from side to side, it's usually going to be at a slight angle.
When you smoke it low and slow, you'll get a better smoke ring. When you get up above 300 degrees, you lose quite a bit of the smoke process.
Overall, good job. Keep at it. You'll pick up little things, (that others won't necessarily notice, but you will,) that will make your briskets better almost every time you smoke one.