This book is an exceptionally well written, scholarly and quite technical discussion of the central issues in the interpretation of quantum mechanics. Bub really knows his stuff and he takes great pains to be very clear. But be forewarned that some of the material is not easy and he does not shy away from technical details where needed, so be prepared to really think. Although he provides an admirably clear and succinct appendix summarizing the needed mathematics, I think prior exposure to quantum mechanics and the underlying mathematics is a prerequisite for really understanding the text.
One highlight of the book is his discussion of the so-called New Orthodoxy, which invokes environment-induced decoherence to putatively resolve the measurement problem. It has been shown theoretically, and empirically verified, that decoherence can cause a state in quantum mechanical superposition (state of coherence) to quickly evolve into a state that, ignoring the environment, is indistinguishable from a classical statistical mixture, i.e., one in which there is no quantum mechanical interference among the individual superposed states. Bub argues, convincingly to my mind, that decoherence does not resolve the measurement problem in principle as opposed to, as some say, "for all practical purposes". He also provides cogent criticisms of the Everett-style many worlds and consistent-histories approaches, which some have used to supplement decoherence.
If you are looking for a serious discussion of the many key issues in the interpretation of quantum mechanics, this would be my first recommendation.
