This is probably the best tech book I have ever read, but I may be biased because I came into it already immensely interested in the subject. As a programmer who was a bit wary of tackling the fundamental inner workings of bitcoin, this book has really given me the knowledge and confidence to fully immerse myself in bitcoin from a software standpoint.
I'd recommend this book, without a single reservation, to any developer or techie interested in learning about what may be one of the most important technological innovations of our time.