In a previous blog post I reviewed ASP.NET AJAX in Action and walked away with what I felt was a good grasp of ASP.NET AJAX and felt I could get started implementing AJAX in our main enterprise level application.  Recently, I borrowed Professional ASP.NET 2.0 AJAX (Published by WROX) from a friend to see how it compared.

Overall I feel the AJAX in Action book was a far better book.  The amount of detail that was covered in that book was surprising.  After reading the the WROX book, I felt the book did not really go into enough details about how things work and how to do real world tasks with ASP.NET AJAX. 

The wrox book covered some of the basic concepts related to the update panel and the script manager.  There was also a real good introduction to JavaScript for the developers that may not have much experience to the language.  Finally the WROX book had a chapter on creating a control.  The chapter first created a client side version of the control, and then converted it to a server control.

While the WROX book covered the update panel, script manager, and control creation, I feel AJAX in Action went into a lot more detail about these concepts.  The AJAX in action book spent 2 chapters covering the update panel.  When it came to control creation, the level of detail that was covered between the two books do not compare.  The chapter in the WROX book was almost like an entire code listing of how to do it, with very little explanation.

To wrap it up, I feel I made the right choice in buying ASP.NET AJAX in Action as it was a far better book.  If you are looking at these two books, I would definetly pass on the WROX book as all of the information in that book is covered in the AJAX in Action book.