Oh my goodness, this book was so good. Yes, it was slow and dense at time, relying on a lot of intentional worldbuilding and info-dumping, but I actually really love that. 
 Unlike some of the mediocre books I've read as of late (and even some of the quite good ones), there is no doubt that this world is fully realized. Sanderson knows the politics, religion, geography and history of this alternate history he's created. And he knows the laws and rules of Rithmatics inside out. From the way the characters speak and act, to what's hinted just slightly out of view, to the draws that preface each chapter, it's a fully realized and tightly constructed world. 
 Not to say that it wasn't confusing at times. I spent a lot of time at the beginning of chapters trying to really understand the Rithmatic drawings. But it got easier and easier each time, as I became more familiar with the rules. I can understand, though, how some people might feel bogged down by the complexity. 
 But truthfully, this book made me remember why I love epics and fantasy so much. It's bolstered my courage to pull some of those chunky books off the shelf and give them a go. Because I adored the way this book was set up. 
 Also, this book was supremely creepy. Sanderson has successfully made me afraid of chalk. Seriously. It's more his storytelling, it paints such a clear narrative picture (combined with the well placed illustrations) that just have my imagination acting overtime. I was more freaked out after the prologue of this book than I ever was during 172 Hours on the Moon--which has been lauded as genuinely terrifying (but that I found lacking). I loved it. 
 That said, I've gone with 4.5 stars instead of the full 5 because of a few minor quibbles. 
 Because this book is very plot heavy, I found my attachment to the characters came second. I enjoyed everyone well enough, but I was never totally attached to them. Granted, this is the first in the series, and about half the length of Sanderson's usual fare. It's not a dealbreaker by any means here, just something I'm looking forward to Sanderson expanding upon in future books. 
 And then there's the whole thing about women in this book. Okay, look, I get it. You're setting this in an alternate early 1900s. I understand that the few disparaging comments about women are meant to be "period accurate". But the lack of female diversity was a real bummer. It just felt like a big old boys club at times, and I think there could've been more representation. 
 Still, despite my annoyances, this was a fantastic book. I read it almost reverently. And smacked my hand against the front cover when I was done because it was just that good. Highly recommended!