Although I wish I could get this in the written format, it does still succeed as a graphic novel. GRRM's strength is his characters and his dialogue, but as I've seen from this and the first Dunk and Egg novella, his plotting is also masterful.
There are a few surprises in this book, some great worldbuilding, and as always the conflict is potent. A highly recommended read. The information we learn about the Blackfyre Rebellion is worth the price on its own, but I'm quite happy to say a fantastic story is there to be enjoyed as well.