My review on Hadoop : The Definitive Guide 3rd ed. is now online at DZone. Here is the “One Minute Bottom Line” of the review.
Overall the writing style is accessible though bit verbose at times. The logical progression of content is ok for the most part though some sections are deep inside chapters making it bit hard to find (e.g: A good example would be the section on Cascading). Also I think the section on writing a mapreduce application is bit too deep into the book. However with those aside I think the book is a good reference, capturing new developments of Hadoop and its ecosystem of projects sufficiently across its breadth.
Thanks Mitch for giving me the opportunity to review the book. You can read the full story from here.