I raved about Grace of Kings, but count me among those who think Wall of Storms is the better book.
The pacing varies quite a bit, but the flashbacks--which tend to be the slower parts--serve the "main" character (it's really an ensemble, but the main audience stand-in) well. One of the leaps forward from GoK is that the women are given MUCH more to do, to the point that they sometimes eclipse the male characters. And there are enough women with sufficiently complex and varying perspectives that Liu avoids the trap of making one or two female characters near-perfect. And like reality, all of them believe they are doing the right thing with what they have to work with at the time, even when the consequences become disastrous.
And one of my favorite bits: I never expected to see a debate on agribusiness in secondary-world Big Fat Fantasy.