Generally informative book. The author is without question an expert at data analysis and its management. In fact so much that he cannot resist to to digress into MDX, data cubes, SQL, and various other sophisticated data analysis methods. His side-trips make the book less readable and leaves the reader questioning his focus. While the non-DAX matters discussed are very informative, it would appear that the writer could have possibly handled these digressions either as footnotes, or as Appendixes. The book already contains 3 Appendixes and the subjects covered therein are at times repetitive of information covered earlier in the book.
The author could make his book far more readable by citing the navigational instructions in more logical sequence and format. For example, if a command is located buried in the Ribbon, why not start with what the reader sees and drill down from there. The writer seems to prefer to use the quite the opposite, the "drill up" method, which makes the book less readable and forces the reader the do mental gymnastics. Highlighting the COMMANDS in BOLD, or ITALIC letters or some other similar way, even if just capitalized, would make reading much easier by separating the navigational instructions from the text.
The book could certainly have been more readable had the author not wrote it in second person. As it is now, the reader suffers through, or attempts to ignore, hundreds of pronouns .. YOU and YOURS, not one of which advances the thesis of the book. Expecting the reader to read "your data".. and "you do this" .. "you do that" gets boring rather quickly, especially when some sentences contain 3 or 4 "you-s" and "your-s". (If you had to scratch your head with your hand, when your eyes saw the jumbled order of words in the review title, it is intentional and intended to draw attention to the awkward, illogical manner in which command navigations are handled in the book.)
The writer represents that the reader can download from a cited website 250 DAX formulas. The formulas download into .txt formatted documents with no explanations, or any further advice. It is not quite clear from the book how exactly the reader/user benefits from downloading them. The formulas appear to have been formatted to be used with the various data tables and databases discussed in the book.
Discounting the aforesaid organizational and writing style deficiencies, the book is well worth reading; it is certainly a very valuable, very useful reference manual on the subject of DAX formulas; and its price is most reasonable.
I am glad to have bought and read the book for it certainly gave me a good insight, into DAX and will keep it within reach as delve into Business Intelligence type analysis using DAX formulas, and POWERPIVOT in EXCEL 2010.