As a software developer with no recent experience developing on OS X, I needed an introduction into Apple's IDE to get myself up to speed quickly. This book accomplishes that goal to the extent that, while I might still have unanswered questions about some specific details, I'm no longer overwhelmed by Xcode and feel confident that I know enough to get my job done and where to look for answers to those questions.
Even though it's billed as a `developer reference', it does not in my opinion completely live up to that claim. While the book is thorough in its treatment of its `mechanics', it does not exhaustively define every detail of the IDE. For instance, the specific compiler and linker options are described only summarily. Since I'd expect to internalize the mechanics after some regular use of the IDE, and it's those specifics that I'd have trouble memorizing, I don't expect I'll be needing to refer to the book very often in the future.
Some of the sections could have been a little stronger; in particular, I found the description of workspaces to be somewhat inadequate, and found no explanation of how to set up inter-project dependencies. The treatment of `schemes' I also found a little weak, though I will say that what I learned about them from this book absolutely saved me from endless confusion and frustration when I was debugging problems with a multi-target project.
Going one level of detail further would, in my opinion, have made this title absolutely worthy of five stars.
The book is straightforward about what works well and what doesn't. Compared to some other product-tutorial books I've read (Microsoft's "Inside-Out" series comes to mind) that uncritically glorify the software they describe, this book is refreshingly frank, so the author quickly gained my trust as somebody who knows the IDE well. In particular, his description of the confusing and scattershot structure of Apple's documentation helped me understand why I'd been so frustrated approaching Xcode from that direction.
From a typographical perspective, some minor changes would have helped me: while describing the toolbar, having the icons in-line with the text would have been useful. The figure legend type isn't sufficiently distinct from the body type, making the flow more confusing than it needed to be. Very occasionally there were discrepancies with respect to the later version of Xcode that I was using (4.6.1). None serious problems, though.
The book tries its best to be language-agnostic; while it may be tilted slightly towards the Objective C camp, I don't feel it hampered my understanding of the IDE for C or C++ development. I've been looking for a similar book in the Visual Studio realm for a long time, but those appear geared to novice programmers who are also trying to learn a particular programming language at the same time. In that sense I'd say the OS X community is fortunate to have a quality title such as this that deals so specifically and thoroughly with the IDE itself.