Discovery still continues to impress me with the best use of it since the original TOS episode

Yes! Halfway through I thought to myself that damn, they are so great at using the mirror!verse and it's such fun to watch. It feels relevant to the characters and taken seriously in a way it just didn't in other shows. (If they manage to thematically tie it into the current situation of the Federation in some small way next episode, that'd be the icing on the cake, but I'm also entirely fine with it as an exloration of the Emperor's character and her relationship with Michael.)