After reading Faith of the Fallen, The Pillars of Creation let me down.
It seems like a great big detour away from the plot. I actually don't mind that Richard and Kahlan aren't present until the end, nor do I mind the plot of this book itself. Those factors alone would have made the book fine. The book itself, however, is just poorly written.
The protagonist, Jennsen Rahl, is half-sister to Richard and a "hole in the world"--ungifted, no gifted person can detect her with the gift. Coincidentally, this gives her the potential to destroy all magic in the world. Oops.
I found Jennsen an annoying character. I don't object to having antagonists manipulate the protagonist into doing their bidding--that is fair and also fun. Jennsen is just not that likable, at least in my opinion. The way that she resolves certain predicaments was improbable. She manages to avoid a snake in a swamp--one that apparently eats everyone else who tries to get past it--and arrive on the doorstep of an expository sorceress. I'm willing to accept that her heritage bequeaths her certain abilities, but it's all very convenient.
Oba Rahl, another of Richard's half-siblings, seems entirely unnecessary to the entire plot of the book. He overlaps with Jennsen at certain points, but Goodkind shunts him off to the side during the climax (which I thought was supposed to be the most important part of the book, so I'm very glad that Mr. Goodkind has corrected me on that). Oba shares traits with Darken Rahl: he is ruthless and has a taste for cruelty. Unlike his father, however, Oba is not cunning. And he hears voices, which can often be bad for your health.
It's a shame that this book wasn't better. I enjoy it when a series takes the time to portray the main characters from the point of view of secondary ones. But at the end, the story was just not very satisfying.