While you have few reviews, a single bad review lower the overall rate. Today we got a bad review, probably because there was a misunderstanding about the scope of the book. I feel the need to give some information to help other possible readers to make a good choice.
First of all, I suggest everyone to take a look at the book contents. It already describes pretty well what you should expect to find in this large book. In the same place, you will find the links to download two sample chapters of the book. They are not the toughest ones, but they show you the general approach that is the one of explaining LINQ, addressing its use with other libraries (like ASP.NET, WCF, WPF, WCF and so on). This does not mean that we cover how to make data binding works of how to write an application in WPF. We assume that a particular library for communication or presentation is already in your skills. We only concentrate our attention on data query and manipulation.
Another point is the language. We used C# as a language of choice, and used VB.NET only in chapters where the features and/or syntaxes are significantly different (XML integration is one of the most important area for this). Converting existing C# samples in VB is very simple, and we always highlighted when major differences are expected. There are parts where only the VB syntax is available (see XML) and other parts where C# doesn't have correspondent VB syntax. All these differences are well explained in two appendixes, one for C# and the other for VB. We had to make this decision because space was limited and we had a lot of content to put into the book.
I hope this will help you. Please contact me if you have any doubt and/or would like to give other feedback.