When I read the product description for this item, I was expecting to get something like a cross between the Dungeon Master's Guide (DMG) and the Player's Handbook (PHB). While this book IS something like that, I can't say it's really what I was expecting, and it's not at all what I wanted.
The book is really nothing more than a few sections from the DMG and a few sections from the PHB cobbled together and reorganized into a single reference. While that may sound like an excellent idea, the final execution is, at least to me, somewhat lacking.
For starters, the book wastes quite a bit of time and page space reiterating (yet again), what a role playing game is, how the core D&D mechanic works, and even - yes - what dice you need. Anyone who plays D&D already obviously won't need this information, and I'm not exactly sure who the authors (or Wizards) think they're targeting with this section.
The next sections are nominally more helpful, with a summation of the planar structure of the worlds, a quick recap of all of the deities (including the ones not described in the original 4E PHB), and an overview of the default D&D "world". This is followed by a description of how to create a character, and how to read a character power card... and a complete lack of a list of any actual player power cards. I wasn't exactly expecting a book that contained all of the powers included in Martial Power or Divine Power, etc., but it might have been nice if it included all of the basic powers from the PHB, or even just those with official errata.
The book continues in this vein: presenting information about how to understand parts of the other books without including any actual content. Pretty much the only really useful section was a reprint, along with some much-needed restructuring, of the basic combat rules from the PHB. The sections taken from the DMG included how to build an encounter, and the treasure tables, but nothing that really seemed necessary to keep in a separate manual.
I guess what I was really expecting was a single, handy reference manual that contained all of the most frequently referenced rules and tables from the other books. This one doesn't even include weapon and armor tables!
I think what it comes down to is the simple fact that I, as a reasonable experienced D&D 4E player, was looking for something that this book simply wasn't intended to deliver. I guess if you're a fairly new player, or someone who wants to play but can't afford your own copies of the Player's Handbook and the Dungeon Master's Guide, then you might find this book useful. At the same time, however, there isn't enough information in this book to actually create and play a character...