I'm giving this four stars due to the strength of the last 100 pages or so, plus my faith in Sanderson that this will be a worthwhile and necessary first book in a very long series. There's not many authors that I'd sit through a 1200+ page prologue for, but Sanderson is one of them. It's a weird feeling to rate a book on what it will "probably" be just as much as what it was to me during the experience of reading it, but I feel like this book really does require a long view. If I get a few books into The Stormlight Archive (when they're written, of course!) and realize this book is a vital beginning, I'll revise my rating up. If it doesn't live up to the promise, I'll revise it down. 
 Either way, there was a lot to love about this. It was a slow burn, and I found my patience being tested many times, but ultimately I'm glad I finally tackled this. I'm dedicated to the Cosmere, and since the Stormlight books seem to be the keystone series so far, I'm in it for the long haul. ^_^ 
 2016 reading challenge: a book over 1000 pages