The book is excellent for its extensive coverage. In addition to discussing growth models, as the title suggests, it includes discussions about the tools used to solve these models. Such topics inlude the theory of optimization in both continuous and discrete time. However, for extensive treatments of dynamic programming and continuous time optimization, there are better books devoted to those topics alone, however, it is nice to have the important results all in one book.
Another nice feature of the book is the discussion of the fundamental theorems in a variety of settings. It is really convenient to have these, along with detailed proofs, in the same book that covers specific growth models.
Having said that, the most important thing is that there is a very solid treatment of economic growth, both from an empirical and theoretical perspective. Most of the recent developments are given at least some discussion and excellent motivation. To have all of these covered in one book is really amazing, and the author ties it all together very nicely.
I find the exercises to be crucial for understanding new material, with some being easy and others quite difficult. I think this book is a must have for graduate students who want to get there feet wet in growth theory.