Mr. Redmond is an excellent authority on Microsoft Exchange, and the depth of his knowledge is apparent in this book. However, I did not find the book very well written or easy to read. On the cover there is a bullet that says, "Supremely organized, packed with expert advice." The second part of that is true.
My own background is someone who has worked extensively with Exchange from version 5.5 to 2003, but I skipped 2007 and wanted to get up to speed on 2010. If that describes you as well, this definitely is not the book for you; suggestions at the end of this review. If you are familiar with Exchange 2010 already and simply want to learn more, and don't care how the information is presented or even particularly what you're going to learn about, you might enjoy this book. Many other reviewers clearly have.
Mr. Redmond, by his own acknowledgment early in the book, took a "shotgun" approach to writing this text. He didn't have a particular strategy for what to write about and in what order. He sort of jumped in and did a brain dump, and wrote chapter headings as they sort of made sense. But to be sure, you'll find things in strange places, and if you overlooked his comments on his writing strategy you will be scratching your head wondering why various tidbits are where they are.
In that the book is a brain dump, it does capture a tremendous amount of information. But if you're trying to learn about Exchange 2010 without a background in it, the order of things makes no sense. Chapter 3, for instance, is all about Exchange Management Shell, the PowerShell command line method of administering Exchange. And it goes into a fair amount of depth. But at this point in the book we have not discussed Exchange architecture at all. We don't know what a Client Access Server or a Hub Transport Server is. We haven't looked at how Exchange is administered from the GUI. Mr. Redmond even starts talking about how PowerShell has advantages over the Exchange Control Panel in this chapter, when he's never mentioned it before so we have no idea what the ECP is or what you can do with it. So we're learning how to manage Exchange from a CLI when we don't even know how to architect a basic Exchange installation yet. Makes no sense and makes it impossible to take in the information unless you already have a good background in it.
Once I got a couple hundred pages into the book, I realized this was not the book I needed to be reading, and so in full disclosure I didn't finish this 1000+ page tome on Exchange. So I can't say definitively that all the information I'd need to learn about how to install and manage Exchange 2010, coming from an E2K3 background, isn't in there. But from the table of contents it is not at all apparent that there is any substantial discussion of Exchange installation, design and implementation. There is a lot of discussion of management tasks.
Mr. Redmond also spends a great deal of time going over RBAC, role-based access control, and its features in Exchange 2010. There are chapters on legal compliance and retention, and other features primarily of interest to larger organizations. From his emphasis on these topics and his overall style, I think the target audience for this book is more administrators (not designers/engineers) in very large (10000+ seats) organizations, where roles are highly defined and job functions of limited scope. People who work at smaller organizations probably won't be very interested in a lot of this discussion. Which is not to say these topics are not relevant, but rather that there is not enough discussion of the more fundamental topics.
I didn't expect a book called "Exchange Server 2010 Inside Out" to be understandable by someone without a good Microsoft background, including Exchange background. But I did not expect that in order to get much out of it, you already should be quite familiar with the product.
Since Mr. Redmond reads these reviews, I'd like to propose the possibility that he has been working with Exchange for so long, and in such large environments, that he has become distanced from what "average" administrators need to know, and for his book on Exchange 2013, it might be helpful for him to take a step back and write a book that goes over the architecture, implementation, best practices, backup and restore, etc. of Exchange that can be understood by people coming from backgrounds of various versions of Exchange, or no background, but with a good technical mind. We need people who know the product very well, and have used it for a very long time, to write books like that, given how spread out the documentation is these days.
So in summary, there is a tremendous amount of knowledge given in this book, and it may be a good read for someone who already knows a fair amount of Exchange 2010 and just wants to pick up some more. But if you are trying to learn Exchange 2010 for the first time, don't confuse this book as "Exchange 2010: The Missing Manual." It is not the missing manual. If you want to learn Exchange 2010 well, read first the Exchange 2010 Best Practices Guide, which covers design and implementation on a very good and practical level, and then read the Exchange 2010 Administrator's Pocket Consultant for the very down to earth how-to. Once you've got all that down, perhaps this would be a good read.