Strengths: This is probably the most comprehensive book on any subject that I've ever read. Huge amount of detail on anything running related, especially anything health or fitness related. Challenges a lot of preconceptions such as hydration.
Weaknesses: Don't buy it if you don't do detail. Minor OCD is probably a prerequisite. Heavy (both as a read and physically).
Overall: My sons bought me this for Father's day and its the best running book I've ever seen. I'm still working my way through it.