I have to separate two different responses to the episode.
First, I think is looking at Dany's heel-turn within the larger arc of the show. I know a lot of people felt betrayed by that. But there were plenty of indicators that her will to rule was even bigger than her sense of mission (free the slaves! Break the wheel!), and that she could be utterly ruthless. I do think this is probably Martin's plan with her but as he writes from inside a character's POV it won't seem so abrupt or unearned.
I don't think it was out of character and I don't think it was in response to Missandei being killed but rather the culmination of her being increasingly isolated. Losing her close confidantes in Jorah and Missandei. Being betrayed by Varys (and really Tyrion). Losing two dragons. Losing a lot of her Dothroki and Unsullied troops defending Winterfell and then treated like shit by the North. And ultimately Jon's rejection of her (and also his betrayal by telling Sansa and Arya of his parentage) nudged her to rule by fear.
The other perspective is to consider how the episode was shot/directed/written on its own. And in that case I thought it was far more effective than The Long Night, or The Last of the Starks. I thought Clegane Bowl was spectacular and horrifying and ended that particular arc well. I thought Sandor and Arya's scenes were effective and had enough weight to turn Arya off her path of vengeance. I was glad they decided to show the slaughter on the ground from Arya's POV. It really reminded me of how Syria has been destroyed, but also there were clear callbacks to 9/11 (in the ashes floating down and the plaster streaked faces).
Also, the characterizations were less driven by stupid plot convenience and more in line with what we've seen. Jaime's redemption arc comes up short because his love/obsession/sickness with Cersei is who is. And he made that decision when he left Brienne.
Tyrion used to be somebody who drank and knew things. Then he stopped drinking and became stupid. WTF with him thinking Cersei would be happy scuttling off to Pentos with Jaime and living in a hut with a one-handed fisherman? His scenes with Jaime were affecting but another betrayal of Dany which will probably get him burninated. And for what? To let a psycho and a pussywhipped fuckup die together?
Are we supposed to believe Cersei and Jaime died in that scene? I suppose it will be revealed in the rubble next week one way or the other.
Things I Want To See Next Week But Won't
Bran jumps up out of his chair and yells "Psych!" Then tapdances down to the nearest ship and heads to Essos where he becomes a tree, but a tropical one with tasty fruit. He only wargs into parrots and becomes a real sassy bitch committing gossip all over town.
Yara seduces Brienne amidst the sounds of much squeaky leather and cute-awkward scenes of their sheaths getting entangled.
Thormund bandaging up Ghost's ear and saying, "Who's a good boy?! Who's a good boy?!" while Ghost's tongue lolls out as he gets scritches.
Sansa converting Winterfell into a stylish ski resort with a cable driven skyway running all the way to the Great Wall. She keeps the armor like black outfits because they set off her hair and basically turns into a younger Oleanna.
Arya runs away and joins a theatrical troupe in Essos where she becomes the premiere drag king attraction in the land, taking a series of boytoy lovers.
Gendry and Jon settle into paunchy middle aged white guy dulldom, take to wearing khakis and polo shirts and punching each other in the arm affectionately during jousting matches, then turning away and getting misty eyed over their lost loves.