Disclaimer: I contributed a tiny bit of Linux-specific information to the book, so I might be a bit biased here.
I'm definitely biased by 20+ years of working with Csound, and as a long-time user I am pleased to see this book. There's no lack of documentation for Csound, but Csound Power provides a missing part - a normal user's introduction to the installation, configuration, and basic use of a deep and complex environment. Csound Power is relatively up-to-date (Csound development is a very active track), and the book's tutorial material includes an excellent introduction to Andres Cabrera's outstanding CsoundQt, a cross-platform IDE for writing, editing, and running Csound code. Other noteworthy material includes a great tutorial on building your own synthesizers (Jim's an expert on the topic) and a chapter titled "Thirty Opcodes You Must Know" that significantly reduces the new user's initial confusion when faced with Csound's hundreds of opcodes (i.e. processing modules). Another neat chapter presents the possibilities when Csound connects with other interesting music and sound software - e.g. Max/MSP, AbletonLive, Pure Data (Pd) - by using MIDI or OSC messaging, or by writing control programs in general-purpose computer languages such as Java and Python.
Minor critiques: No information regarding Csound on mobile devices, and no disc with code examples and other relevant material. Frankly, neither lack bothers me at all, but some may wonder why it's missing. Development of Csound for mobiles has only recently begun to move forward, I doubt there was much relevant information available while Jim wrote the book. Regarding the disc-with-code: Sorry, I'm Old Skool, I think it's good practice to copy the (usually brief) examples into an editor. After all, Csound is a programming language.
Jim Aikin is a well-known figure in the world of music technology, and his writing has always been clear, informative, and uncomplicated. Csound Power continues his fine work, to the great benefit of Csound users everywhere.