The Age of Madness ends in the place that it has to end, I think. All of the larger plot and character arcs make sense. The Weaver's full scheme is revealed, and is utterly logical given what we know of the world of the First Law. People suffer for reasons just and unjust, make necessary decisions that destroy their souls, and achieve long-desired goals only to discover that what they wanted and what would have made them happy are far from the same thing. It's Abercrombie, in other words.
The plot architecture of The Age of Madness is probably the best that Abercrombie has ever produced, but despite that, I think the work as a whole is a step below the original First Law trilogy. There's a couple of reasons for this.
The first is that, while Abercrombie's better than ever at getting the pieces where they need to go, the process of seeing them advance across the board is not quite as interesting as it has been. One of the keystones of fantasy is seeing characters reveal their natures through entertaining action. Watching Bayaz's motley crew stumble their way across the Old Empire, bickering and blundering the whole way, was some absolutely first-rate character driven adventure full of wonderfully revelatory dialogue and fascinating displays of incompetence, competence, and growth. _A Little Hatred_ had a lot of the same fascination in its early stages as we met the colorfully-drawn characters of this new world and observed the fascinating mechanics of an industrial revolution swallowing up a fantasy kingdom. _The Trouble With Peace_ didn't fully sustain the momentum; there was a great deal of scheming in salons and political maneuvering that, while proficiently written, didn't fully fire my imagination. I had thought that this was a middle-chapter problem, but it's back in _The Wisdom of Crowds_, and it's considerably worse. The business involving Rikke and Black Calder in the north moves along at a fair pace, albeit with a couple of twists that are telegraphed a bit too broadly to be fully effective, but I'm afraid that the French Revolution redux in Adua bogs down pretty badly. Part of the problem is that we've already seen much of the same in the previous book's Valbeck chapters; the horror is not fresh, even with the general violence level amped up. Part of it is that the victims of the Burners are, for the most part, people we've never had much opportunity to identify with, and the people we HAVE been taught to care about never seem to be in meaningful jeopardy until the book's final third.
My second criticism is this. In Abercrombie's best work--The First Law, Best Served Cold, and some of the stuff in Sharp Endings--there's a powerful sense that the characters are driving the plot. Here, as never before in my experience, there's a sense that the requirements of the plot are changing the nature of Abercrombie's characters. In some cases this makes sense. Gunnar Broad, for example, is defined by the fact that he allows himself to be the instrument of other people's will, so it is reasonable that events would make him a different man. Rikke's personal transformation has been engineered both in overt ways by Isern and in subtler ways by her own hidden ambitions. Vick and Gorst are true to their own established natures, but also shaped by events in ways that their decisions and ultimate destinies make sense.
In other cases, the changes are jarring and hard to fully accept. Savine dan Glokta undergoes a pretty radical personality shift in TWoC, and the explanation offered is both a bit of a cliche and (I'll be the first person ever to say these words about an Abercrombie book) a little bit twee. It's great when characters change, but in her case, the change doesn't feel fully driven by her virtues and flaws, nor by the events surrounding her; it feels like something the book needs to happen in order to get her to the place she's supposed to go. These problems manifest in minor characters as well; Tunny's portrayal is so far distant from who he's been throughout the entirety of the First Law saga, and the reasons for the transformation are so obscure, that one has to wonder whether his role wouldn't have been better occupied by an entirely new character.
By far the worst example of this, though, is Leo. It goes without saying that the events that occurred at the climax of TTWP would change a man, but to me, it feels as if half his brain has been amputated. It's as if I'm reading a completely different character, and a far less interesting one. The final chapter in which we see Leo is titled "The Villain", and while Abercrombie is constitutionally incapable of making things _that_ simple, it's hard not to get the impression that Leo has been forced into a plot niche traditionally occupied by somebody else. A fellow with more limbs and less hair.
And while we have all of this astonishing trauma working massive personality shifts in several of the dramatis personae, there's also Orso, sitting in his cage swilling wine and quipping away wittily, his character utterly unchanged. In many respects Orso is one of Abercrombie's most fascinating characters ever, a really interesting spin on the "playboy with hidden depths" archetype, and he's certainly an effective mouthpiece for some terrific one-liners. But to the extent that events changed him at all, it seems to me that those changes were more or less complete at the end of ALH. In TTWP, he's interesting in the sense that we see his hidden strengths revealed and contrasted with Leo's more superficial strengths. In TWoC, he's just a guy who stuff happens to.
The Wisdom of Crowds leaves The First Law universe in an interesting place, and it shows many of the same strengths that have made Joe Abercrombie my favorite fantasy author. But I do feel he's taken me on more interesting rides.