I've read most of the book and I have to acknowledge that, despite the fact that the subject is tough, the explanations and writing do a good work. However, I found that there are few examples, and some points should be treated more deeply.
The book insist in the use of annotations as the "proper" way to configure and use Hibernate. However, hibernate manuals go for other way. Conclusion: when you search in internet for a specific solution for your problem using annotations, you find very little examples. It should be a better approximation to the problem jus simply using the same tools the others are using (despite the fact that I have to recognize that annotations are a cleaner aproximation to the problem of configuring hibernate).
A final point is the availability of this book as an e-book. The book is served as a pdf file password-protected. Many tablets and ebook readers doesn't support it, so i have to break the password as the only way to simply read the book in an android tablet.