They definitely took some shortcuts from the book with Tyrion's journey to Daenarys. I was really looking forward to him being a clown.
Really? I thought that (and the prolonged Tyrion downward spiral in general) was one of the more grating parts of the book - very glad to see it cut out.
The challenge the showrunners have faced is salvaging a heroic journey from the quagmire Martin was plunging his few remaining heroes (Dany, Snow, Tyrion) deeper and deeper into in the 5th book. That meant cutting short Tyrion's wallowing with the pigs, and fast-forwarding the glacial pace of the White Walkers to spice up the Jon Snow storyline that had gotten lost in the Wildlings.
There's not much they can do about the diaspora of the subplots though. Even with the Ironborn, Maester Sam, Recruiter Davos and Dornish Dany-quest plots entirely cut out, there are still way too many threads to weave together. Bran and co. are still out there, doing something important we just can't remember what, Brienne of Tarth is still waiting to be of service, Littlefinger is out conspiring somewhere, Arya is wasting enormous amounts of precious story time learning to be a petty assassin in a backwater port, Cersei and Margaery are getting inexplicably pwned by 99 percenters, bad Maester is building a zombie Mountain, Jaime's lost in Dorn, Stannis is freezing his butt off somewhere in the north, Ramsey's doing his Frank Miller bad guy routine on Sansa & Theon, and Dany's dragons are either chilling in the basement or flying unchecked across the countryside. And I'm sure I left some people out. That's just way too much to work with.
It's a shame Martin didn't have a better editor - such fantastic ideas, such a rich world, but not enough discipline to turn down the rabbit trails and keep his eye on the prize.