I gave it a 7/10.
This was an episode I was expecting for a long time. I always thought Dany would become a darker character, even though I didn't quite expect this to happen in such an overt manner. I thought the reactions to Jon Snow's revelation and the dynamics between the characters were interesting.
With that being said, I understand why some people take issue with this episode. The attack by Euron didn't make a lot of sense for various reasons. The negotiation scene was highly unrealistic too. I also felt that her advisors turned on Dany a bit too quickly.