The biggest reason this book won the 2012 Nebula and Hugo awards was because it was constructed to speak directly to the judges (SF and Fantasy writers and avid fan-readers) all of whom connect with the main character because she "thinks like they did/do" when it comes to books in general and, specifically, Speculative Fiction.
It gets my 3-star-forgettable rating for trying so miserably hard to depict late-70's England/Wales that it loses every bit of suspense and tension when every action a character might take, or sentence a character might utter, was run through a would-that-really-happen filter before it hit the page. I'm willing to bump it to 3-star-plus because it lists titles which I'll put on my 'to read' list.
It didn't deserve the Nebula. Or the Hugo.
Patrick Rothfuss's The Wise Man's Fear deserved that honor (but wasn't nominated). I suspect there are huge machinations going on behind the SFWA and WSFS scenes that continually prevent the best of the best from ever being nominated. For all I know, Rothfuss didn't even want to be nominated.
It is probably just like presidential nominations. Was John Kerry the best Democrat of all the Democrats who could have beat G.W. Bush in 2004? Is Mitt Romney really the best Republican of all the Republicans to challenge Obama this year? Obviously there's more going on behind the curtain than we know about.