A couple of the reviewers complained about too many screenshots. Another one complained about it being too easy. I personally don't view either of those complaints as faults of the book. If you already an experienced Entity Framework Programmer then you probably aren't going to learn a whole lot of new things by purchasing a book on the latest version of the Entity Framework. The upgrades in Entity Framework from 3.5 to 4.0 are incremental, not revolutionary.
Even though I don't agree with a couple of the other reviews on "why" this book is horrible. I do agree that it is horrible. And the most glaring reason I would not recommend purchasing the book is because of a severe lack of editing. There are typos and grammar errors constantly throughout the book. There are also code logic errors throughout the book. Chapter 13 on Data Binding with the Entity Framework has to be the very worst in terms of logical errors. For example, on page 237 of the book, the author shows an excerpt of code, that contains C# statements that modify a dateGridView. On the current example, he hasn't even instructed the reader to add a dataGridView to the Windows Form so your project will not compile. He does go on to instruct adding a dataGridView later in the same chapter(on page 239) to build on the example. But the point is, the code excerpt shown for the current working example on page 237 will not compile if you are following along with the book in page order.
Another example of logical errors. On page 243 he shows the following event handler being implemented as follows:
private void productModelBindingNavigatorSaveItem_Click(object sender, EventArgs e)
Apparently, he forgot that he already implemented those lines of code in the same event handler just 1 page before. There are at least 2 other logical errors in this chapter but I think I've given enough examples of this problem.
The last reason you might not want to buy this book, if you haven't already, is because it is already outdated. The author talks about using a ContextBuilder in a code example on page 175. The ContextBuilder class he uses in the example is no longer the recommended method for creating an ObjectContext when using a code-only approach for your Model. Of course, this is no fault of the author or the publisher. Just an unfortunate consequence of how fast technology changes.
This book would be pretty good if it had been properly edited. But it wasn't.