I finished ADWD tonight, so I'm all caught up and waiting with everyone else.
I thought the stuff set in the North was all very good, and most of the rest of the Westeros stuff was also good. However, Meereen is a giant narrative drag; I just don't give a rat's ass about that place.
Mereen was a bit of a drag, yes, but otherwise my favorite part of ADWD was the plot that took place in Essos. At the moment I'm kind of "Westeros-ed" out... We've "visited" all the cool places there, it seems, whereas Essos is a grand unexplored continent.
The massive world building/history on display in Tyrion's journey is my favorite kind of fantasy writing.
Really excellent stuff. And the Valyrian history is so interesting - I'm sure GRRM will reveal more in the last two books.