I've loved every book in the Princeton/SFI "Primers in Complex Systems" series, and this one holds up the tradition. Each one provides a curated review targeting some sub-domain of the massive world of complex systems, and they generally do a terrific job balancing technical, domain-specific exposition with accessible, multi-disciplinary examples and wider blue-sky speculation on the open questions and implications.
I picked this one up as a replacement for an introductory spin glass textbook when I started working on a new (social science) research project. While certain parts seemed of primarily technical interest from my point of view, particularly chapter 7 (on various scenarios for the local-interaction EA model), I found it thoroughly engaging and useful in getting acquainted with the basic flavor of the spin glass literature. For example, I'd often encountered "broken symmetry" arguments from physicists and never really understood their significance until reading this. One minor quibble: I was really hoping for some coverage of coarse-graining and the renormalization group approach, which I understood to be an important part of the 'hierarchical organization' story, but I now feel equipped to delve into those papers on my own!