The first couple of chapters of Feast of Crows was difficult reading, but after rereading them I finally built up enough momentum to carry me through the first half of the book.
To help me get up to speed, I googled around and found the following excellent primer which provided me with a nice refresher of the story up to now.
Four and a half thick books and two more to go. Keeping just ahead of the television series to avoid spoilers. Wondering when the next volume will be published.