The first 50% was just so. slow. Nonfiction can be tough for me anyway. Larson was great at weaving the many facts and tiny details into a coherent story that could be followed, but it just seemed to drag on and on until about 60% of the way through. (I use percentages because I read it on my Kindle). I enjoyed the last half well enough, but I don't think I'll be reading any of his other books.