It's the fantasy blockbuster gutsiest of the Decade

Yes, it's even darker and grimmer than the first installment. Martin takes a big chance in keeping the overall tone so naturalistic, but it pays off. Emotional and Physical Consequences of violence and feudal system are spelled out in no uncertain terms.
A small problem is the way lighter elements are not balanced as well with the darker stuff as in the previous book. The most emotionally rewarding relationship here is between a dwarf and a narcistissic whore. Most main characters are dealing with massive dreams from Earlier events and it's sometimes tough going for the reader. Especially Dany is in danger of becoming a stereotypical teen queen; a kind of grief-stricken Debbie Gibson stranded in Saudi Arabia in leather bikinis. I hope Martin gets her to the smae continent with the rest of the characters in the next book and lets her resumer her growth as a character, so vividly portrayed in GoT.
Sansa and Arya are therefore stranded in almost impossible situations; Very down-beat, but so compulsively readable stuff. Catelyn and most of the other characters are trying to put together pieces of Their former lives - all that is very realistic considering what happened Previously, but Martin better move them beyond this phase in the next book to avoid the claustrophobic feel sometimes evident in CoK.
But all in all, it's an excellent, daring follow-up. It's Obvious That major events are stored for the third book, and for a bridge between first and third novel, this is great stuff. As a concept, it's great deed for once people in a fantasy novel Actually have to deal with The Consequences of death and mayhem. It makes it possible for adults to read the Martin Books without guilt.
Of course, the whole thing * is * spinning out of control. There are 8-10 major religions or belief systems, for example. Martin better do some consolidation in the next novel, and kill off 5-15 main characters as well, just to keep it together. Martin makes Jordan look like Enid Blyton! And that's good.