My favorite reviewer on Goodreads indicated that this sequel was a bit tedious because all the boys are yelling "no, it's my throne, no, it's mine, nanny nanny boo boo!" (I am paraphrasing). Yea, that's true. Martin now knows he has a great deal of time to get his points across so he takes that time and extends the story.
But I very much enjoy the ride. What I like most about Martin's tale is that he has given many characters a voice. And that he does not impugn our intelligence by repeating anything he's said before in another character's voice. In fact, an entire battle can take place off-camera: hinted at by one character, and then post-mortemed by another in a following chapter. The chronology flows forward quickly, in other words.
The drawback to this is that poor Catelyn is never reunited with her sons and daughters, and that's just plain ol' frustrating. I fully understand the plot device, but I would like one reunion, please, before Book 3 is over?? I understand that Books 4-5 are split evenly between the characters of the South and the characters of the North, so obviously my frustration is only going to increase.
In cases like these, it's important to heed Neil Gaiman's advice: "Wait. Read the original book again. Read something else. Get on with your life." (read the rest of Gaiman's post here: http://journal.neilgaiman.com/2009/05/entitlement-issues.html)