"If you ask, she will answer. If she asks, you must reply. A steerswoman will speak only the truth to you, as long as she knows it—and you must do the same for her" - it's an interesting premise, and it brings a lot of great questions out about the truth, the nature of truth, and what it means.
The best part of the steerswomen is their search for truth and information for the sake of truth and information. They are purists, they are true scientists, and they are open.
In this world they're pitted against wizards, people of unknown origin, knowledge, or true occupation (to us), which refuse to share their knowledge at all.
I love that this book doesn't touch gender at all. The entire world (even, it seems, the wizards) are a meritocracy, and it's done in a truly wonderful manner.
Now if the damn thing hadn't ended on a cliffhanger and I knew (for sure) what is a going on, I might have given it a 4.5 or so. It's slow, but the writing does improve from book 1 to 2, and I'm hoping the future books continue this trend.