It is true that the book is a bit heavy on the math but as this book is about ecological theory it should not surprise readers. Despite the theoretical approach, is certainly possible to learn a great deal from the book without a math background. There are definitely more current books on the topic as well as a large body of scientific literature on the subject but this book still remains one of the more used books on my shelf.
The book is very well organized; chapters introduce new concepts incrementally, and the overall flow is very good. The authors start with the classical patch and prey models, adding complexity in later chapters. Separate chapters address trade-offs and simultaneous optimization, dynamic optimization, and rules-of-thumb. The concluding chapters consider model testing and the success of the optimization paradigm.
The writing is somewhat stiff, but still pretty good for a technical work. The bit about how great tits rarely feed on conveyor belts in nature is an exemplar of scientific understatement.
If mathematics are not your strong point, or your background is weak, you will have a hard time with many of the proofs. I skipped over most of these sections expecting to get the gist of the material, only to regret my decision during my comprehensive exams!
While Stephens and Krebs provide a thorough overview of the material, "Foraging Theory" suffers from one serious flaw. The presentation focuses on model development, rather than analysis and interpretation. In order to truly understand these models, the student absolutely must work through "real" examples under the tutelage of an experienced mentor.
The binding has held up very well. The book looks nearly new, despite having been stomped on several times and thrown out a third-story window at least once.
Even after all of these years, "Foraging Theory" still represents the state-of-the-art in optimization-based approaches to behavioral analysis.