I was confused by several of the changes from the books. What's the motivation for killing Qhorin Halfhand now? In the books he had time with Jon Snow before the wildlings got to them, and pretty explicitly laid out the plan, but unless I knew that coming in, I doubt I would understand why he did what he did.
The excision of the Bolton plot is problematic in the long term, but particularly problematic here since now we have no idea why Winterfell was sacked. Timing is also troublesome, because the fact that Luwin is still alive after the sack implies it happened within minutes, or at the most hours, which actually misleads the audience into thinking that it was the Iron Islanders. Especially misleading if they intend to bring in Bolton next season.
House of the Undying... well, we never get to see why it's called the House of the Undying. Disappointing.
I still liked the episode a lot, but it troubled me to see these departures from the book in particular because they cheapen the story. The other changes were either "whatever" or necessary.
RX7