This review will make comments on both the format and the content.
On the format, I read the Kindle version of this book on my Kindle Paperwhite (2012 version). The graphics were readable and the pagination was reasonable, so overall it was one of the better-formatted books I have seen on Kindle. One of the advantages of this format is that you can have the book available to you when you run into something on the phone and need to consult the reference "right now" rather than waiting until you return home to look up the answer in the paperback edition.
On the content, there are a lot of tips, divided into five sections: Getting Started, Communications, Internet, Entertainment, and Productivity. I tried to understand some of the less-positive reviews, and I think that they come down to organization. No one complained that the tips were inaccurate, but everyone approaches the phone from a different perspective and so has different expectations. I will admit that I found some of the tips, such has where to find the button to turn on the phone, to be extremely basic -- but others, such as adding your (non-mobile) contact number to the lock screen so that someone who finds your lost phone can actually contact you, were "ah ha!" moments for me.
In retrospect, considering my experience and some of the other reviewers' comments, I would suggest a different organizational model for future books, divided into two major sections. The first section would be the "getting set up" material. Some of the basic material should be eliminated or gathered into an "if your carrier didn't tell you this when you bought the phone, march right back and make a salesperson show you" section. Then, some of the other tips could be gathered into sections such as "if this is your first mobile phone" (some people actually are just getting them!), "if you are moving from a feature phone / flip phone to the G4," "moving from the G3 to the G4," "moving from the iPhone to the G4," ... Personally, I am experienced with an iPhone and would have appreciated a section geared to bridging iPhone to G4 terminology and features -- something that probably is not interesting to someone coming from an S3 to an S4.
I think that such a section would have eliminated most of the less-positive ratings since everyone could have found the material they needed in a compact section and skipped all the material needed by others.
Then, the second section could be suggestions on which applications make the phone productive and enjoyable. For example, the section on Productivity could be divided into "For those of you who use Microsoft Office on your Windows PC" and "For those of you who use Apple's productivity suite on a Mac." This would let people jump right into the proper section and also let the author write with more detail on each of these cases rather than covering "Productivity Applications" in general. It would also cut down on the perceived duplication / repetition of tips (but, remember that educational theory demonstrates that repetition is good -- didn't you copy and recopy all those spelling lists????). Again, on the subject of making your phone more productive, some tips about having email and sports alerts turned on so that you don't have to continually refresh your email server or move between sports apps would have been right at place in this section -- they are also "productivity" enhancers.
Overall, I gave it four stars since it was a well-formatted Kindle book, had many good tips, and was extensively illustrated with screenshots. However, I hope the author and editor give serious consideration to my suggestions on re-organizing the material in future editions.