Was there filler? If anything, they rushed through storylines (Sparrows ascent, Stannis' downfall). And they could have resurrected the Greyjoys or introduced Dany's suitors if they needed more plot.
My problem wasn't that the season was skimpy, is that a lot of their story inventions didn't work.
This is right. The season's problems weren't the book's problems. The show was just written poorly and rushed everything that should have been important and good. Perhaps if Stannis was struggling over the decision to burn Shireen and starving in the snow for most of the season, then it would have worked. It could have made for lots of really tense, dramatic, and emotional scenes. Instead it was shock and Stannis looks evil and it comes off as stupid.
The book was written well, just bloated with all the useless new POVs, needed to be edited down, and lacked a climax because he couldn't fit it in. If you just look at POVs by themselves, Cersei's and Jon's were as great as every other POV from any of the books. Theon's, Bran's, Jaime's, Davos's, Asha's, Sansa's, Arya's, Barristan's, and Dany's were all fine. Tyrion's and Brienne's weren't good simply because of the bloat. We didn't need all of those chapters for as little as they accomplished.
When I go back and read FoC and ADWD, I skip over all the Ironborn, Dorne, Tyrion, and Brienne chapters and if you do that then I think they're pretty good reads.
I hope this comment from George will shut the mouth of some "fans", who believe they know the characters better than the show's producers (who are doing the SHOW VERSION of these characters...). So much hyperbole and nonsense going about their writing these past two years.
It won't and it shouldn't. The show producers are idiots. Most fans do know the characters better.