(WARNING: CONTAINS SPOILERS FOR THOSE STILL READING PREVIOUS BOOKS)
If you don't know the story of how A DANCE WITH DRAGONS finally came to be, I won't bore you with the details, because there are plenty of other places to read about it, including from the author himself. Suffice it to say, it was a maddeningly long wait for those who have been here from the start. For me, it was only a couple of years, since I came to the series late. Thankfully, I was only left half-mad by the wait.
As for the book itself, well, how could one not be disappointed? We've been given years to get our hopes up. Unfortunately, the problems are more than just unrealistic fanboy expectations. Most of what made the previous novels great--breakneck pacing, nailbiting tension, cliffhangers at the end of every chapter--are gone. There are a few shocking moments, and some tension to be found, but these moments, overall, are rare. Too rare.
Dany, Tyrion, and Jon Snow are all back in full force, but for 80% of the book, nothing of any particular interest or import happens to them. There are 15 other POV characters crammed in between the star trio's chapters, but those are equally disappointing. Victarion Greyjoy, for example, has a rather stirring arc in the book, but absolutely no resolution is offered, so it feels incomplete (obviously). At one point, a very important man is accused of attempting to poison Dany, an accusation which become central to Barriston Selmy's POV chapters, but despite getting resolution to that arc, we never find out if the man in question was guilty, or even if the food was poisoned at all!
I can only come to the conclusion that the Great Split was unnecessary. Dany, Tyrion, and Jon did not need 500 pages between them to tell this part of their tales. Most of what happened in Meereen was window dressing, and did nothing to serve the story. Had Martin given himself a year to figure out where he was going back in 2004, he probably would have come to the same conclusion. So instead of getting FEAST in 2005, we would have gotten a better, complete A DANCE WITH DRAGONS in, say, 2007? Maybe 2008? No matter, it would have been preferable to this.
If you've read the series, I can't NOT recommend this novel, so obviously go and read it if you can. And I certainly can't dissuade new readers from picking up the early books, because they truly are masterpieces. Just be warned that DANCE is not the novel we had hoped for.