This one was very disappointing.
The dragons being ambushed by a fleet is about as realistic as the US battleships ambushing the Japanese planes on December 7, 1941.
Cersei not killing Tyrion is completely irrational and against her character. Didn't she just hire Bronn to kill him and Jaime? And there he is, standing right below the gates. And while she's willing to send a message by killing Missandei, she isn't willing to kill Tyrion? Does he just turn around and walk away.
And Jon Snow tells his sisters his big "secret" which, as Varys points out, is no longer a secret but is information. And Sansa immediately blabs; so much for the power of her word.
Really, I was tempted to turn off the tv.