For such a visceral scene, the potential on-screen (versus the book) is so much higher.

A minor quibble though... IIRC, the Mountain was beat up not just from the fight but from the poison in his cuts. It will undoubtedly come up next episode, but I was expecting the Mountain to be even more debilitated before The End. The way the show portrayed it, Oberyn got beat because he was complacent and his leg got swept. Emphasizing the poison would have put him in an even more dominant position for an even more shocking defeat.

From the early reactions it sounds like the intended reaction was still there, but emphasizing the poison (especially with the Hound's comments earlier in the episode) would have brought added weight to The Red Viper's demise.

Edit: Also, Full Heel Turn Sansa... damn. Dyed hair and everything. What an intriguing shift from the books. I get the need to shorten the storyline, but it's interesting seeing how quickly Sansa becomes Baelish's "partner in crime". Also, I wonder if this is portent of things to come in future books...