Quite liked the episode altogether - the big clusterfuck battle scene was appropriately harrowing and chaotic, with several crowd-pleasing moments (predictable and rather meh Vale Calvary notwithstanding). Perhaps my favorite moment being Jon nearly getting trampled and suffocating under the dead and living alike. Powerful imagery.
I wish Sansa's advice actually amounted to more than trying to hype up Ramsay - and she didn't mention the Vale Knights...why? There's absolutely no reason not to at this point. Despite that, I am enjoying this colder Sansa who is savvy enough to know that Rickon is dead no matter what and is wholly focused on winning the fight. Watching her icily take revenge on Ramsay was, in its own way, like seeing a flash of Lady Stoneheart in the series.
Jon made a horribly foolish decision, but to the credit of the show runners they've been making it clear his judgement is compromised since the Pink Letter set his rage-meter to eleven. And in this case, I was actually entertained and enthralled by Ramsay's cruelty rather than merely bored by it - and as a result I felt the same rush of emotion Jon did. Watching him devolve into a berserker animal was equal parts awesome and disturbing, much like when he finally got his hands on Ramsay, caked in blood and mud and roaring like a wounded beast.
Despite complaints of being a villain sue, Ramsay actually isn't as good as he thinks he is. He kills his own men with crossfire, bails when things get rough, and kills his only bargaining chip for giggles. What irks me though is that we don't see any of his men deserting like Jon accurately believed, which would go a long way towards mending some ill feelings about Super Ramsay.
Mereen's plot resolved smoothly, got some badass dragon action and Tyrion at his best: in a position of power, acting for a higher authority. My only question is why it took a full night before they decided to use the dragons and fight back, but seeing the dragons in sunlight may've just been more visually entertaining. Not sure how Tyrion knew about Jamie's story, maybe he inferred from the wildfire caches he found prior to Blackwater or Jamie told him after returning with Brienne. Makes sense either way, really, and I'm glad someone is calling Dany out for her ITG-esque mentality of repaying savagery with escalating savagery after Season 4 and 5 were spent deconstructing it.
I could ship Yara and Dany. Girl power, heck yeah. Also I was torn between being sympathetic and amused at Tyrion smugly poking at Theon, though Dany for the first time in a long while actually reminded us of her true mission statement and why we liked her in the first place. No speeches about taking what is hers or tearing down castles, just an affirmation that they're going to leave the world a better place than they left it. Good to have you back, Dragon Queen.
Apart from some of the above complaints, my only real problems are preexisting things. Ramsay didn't have much of a villainous breakdown until nearly the end (and even then it was very subdued), he never really got proper credible build-up as a threat beyond the show handing him advantages, and the Northern Conspiracy plotline doesn't exist in the show. Honestly if Roose was the one still in charge (or was indeed killed by Bolton enemies to hamstring them) then we'd be talking a different game.