The fourth book in this series was a little jarring, and a little tough to get into. So many new characters are introduced and so many old characters are absent, since about half of the active storylines are saved for book 5. The real shining point for me was the development of House Greyjoy and it's three insane brothers: Aeron (this guy), Victarion, and Euron (the most insane of all).
Gonna do some more of these if I can find the time.