Looks like you did a nice job on that brisket. Has a nice smoke ring and looks to be juicy too. If it tasted good to you and had a tenderness that was appealing, I would say you produced a perfect brisket. Being able to cut the meat with a fork is a good measure for tenderness. Chewing is a better one though!
For backyard BBQ, a taste and tenderness that YOU like is what you're looking for. In competitions it is a whole different ballgame and I'm not going there..