I really like all three parts of the Dorne storyline in the books (I think those were some of the best parts of A Dance with Dragons) -- Young Griff's invasion of Westeros, Quentyn's quest in Essos, and the Doran/Arianne conspiracies -- so the TV show cutting all three parts out (and eliminating both Griff characters and Quentyn entirely, so that they don't even exist in the TV continuity) and instead substituting this idiotic rescue-Myrcella / Sand-coup storyline is just incredibly disappointing to me.
In the books, Doran Martell is a patient mastermind/chessmaster approaching Littlefinger levels in how he's been planning across multiple continents for decades and is aware of and five steps ahead of every conspiracy in Dorne. On the TV show, he gets ambushed and dispatched by Ellaria in two minutes? In the books, Areo Hotah is a legendary fighter and always on guard and mindful of his surroundings. On the TV show, he goes down without resistance from being surprised by a single stab with a tiny blade? WTF, TV writers? On top of everything else, it's a complete waste of Alexander Siddig, who's a tremendous dramatic actor.
They had so much amazing, complex source material for Dorne, and instead we get get this drek... it's such a colossal waste. Basically, because they cut out the book Dorne storyline, they had to fill out season 6 with moronic filler (don't worry, OP, I'm being careful so that nothing significant is spoiled here) like the 10-minute scene of Missandei and Grey Worm telling jokes, extended play reenactments in Braavos, and the whole ep about a throwaway character and punishing Riverlands outlaws with little or no relevance to the overarching plot.
But that's another entire season's worth of episodes, so how do you fit that in? They had to cut something.
10 minutes isn't going to cover it.