Amen to that, I strongly agree with both of you. The Arya chapters were a repetitive chore through ACOK and ASOS, and did not get interesting again until AFFC - when she actually went somewhere. Again, she is a great character but criminally underused/misused in book 2 and 3.
Honestly, I feel like GRRM was basically stalling a lot of storylines until he could finish the war of the 5 kings, so there was a constant new diversion in Arya's wanderings. Same with Dany, whose storyline I quite like but still, oh she left one city, oh look here's another city she has to liberate... oh yeah, and another! It's all (interesting) diversion to kill time.
Sansa as well kind of just waits around for a book and a half in Kings Landing until she finally gets married to Tyrion and gets whisked off by Dontos.
This is an area I actually feel the TV show can streamline to the benefit of the story, and why I feel Storm of Swords should be one season, not split into two. Just cut out some of the meandering, and get to the meat of the particular storylines.
Plus in TV land, I feel 4 seasons without any Lannister comeuppance or real movement in the Dany storyline is just too much. I'd like to see Season 3 end with Joffrey's death, and if possible, Tywin's death as well.