When this book arrived, it made a good impression because it seemed to cover all relevant topics and also advanced techniques.
Though as someone with previous Objective-C experience I soon stumbled upon some overly complicated code; for example on page 36 it introduces a string with NSString *helloMessage = [[NSString alloc] initWithFormat:@"Hello %@", userName]; ...which requires a release message later on and totally ignores the much easer to use class selector +[NSString stringWithFormat] which would be the "right" way to go. Also easier, because it doesn't require manual memory allocation and release. 'Though there may be pros and cons for a manual init/relase over the class' autorelease on the iPhone platform - but I would at least expect something important like this to be mentioned or explained'.
While this seems a picky example, it sadly represents the whole book, the complicated writing style and confusing instructions. After diving into the CoreData section, I thought of it as an extremely complex topic and was struggling to get my code compiled. After I gave up and went through some other tutorials and examples, I eventually recognized the overcomplicated "everything" of this book. While there is a lot of text, it still leaves out crucial parts and refers to the downloadable completed code; sometimes - because of the long texts - I also simply overlooked important hints. So I found it often more confusing than helpful.
Another irritating issue is the mixed code from the Xcode-template and the customized code. If I'm using an Xcode template anyway, I'm basically interested in an explanation of the template's code and then (afterwards) the customization and newly added parts. Maybe even just the customized part' but by mixing these it gets very confusing and one has to look and compare exactly to find out what one has to do in order to get it working.
I ended up buying the excellent O'Reilly Book "Head First iPhone Development" which gives a much faster and more productive overview into iPhone development, which is quite different in some ways (eg. UIKit -esp. ViewControllers- vs Cocoa/AppKit).
Nevertheless, maybe it's a nice book for someone more patient than me :-/