Sanderson has a knack for inventing flexible-but-well-defined magic systems. Warbreaker's is Breath, which is primarily used to animate inanimate objects, but which also has an assortment of secondary properties for those who've got a lot of it (all of which are defined in the story, but I'm not going to list them out here). The setting treats it more like technology than magic, with background on how animation techniques have been researched and evolved over the course of history. Explanations are intermixed well with the story: no long boring exposition about it. The great charm of this comes when the characters ultimately combine some of these well-established properties of the magic system in unexpected but completely foreseeable ways.
The cast is large and stuffed with likable, interesting characters who generally rise above their archetypes. I quite enjoyed the novel, although some narrative tropes did make me laugh out loud. Also, I miss denouement. The climax of a book doesn't have to be within 20 pages of the end. Really. It doesn't! It's like modern authors are terrified that their characters aren't capable of doing anything interesting after the largest plot problems have been resolved. But quibbling aside, I'll give it a 9 overall.