I recently joined
JTeam, a self declared GWT specialist. Of course I do not want to stay behind so I started reading
GWT in Action.
That was a mistake. There is nothing wrong with GWT, I think it is a very nice component oriented technology in the spirit of Swing and Wicket, which makes it a lot easier to build very complex applications.
But back to the book. Reading the book is a lot like looking at an extremely knowledgeable professor. The kind of professors that know so much that they don't know where to begin. And like with the professor you will eventually get it if you hang on and are able to sort it all out in your head.
Well, I was fed up with it in chapter 5, half way through the 17 chapter book. Here are my mischiefs: 1) the text was constantly referring to chapters further away in the book, 2) it was continuously repeating itself (I had to read at least 4 times that it is okay to use something else then Eclipse), but worse, 3) the text was almost continuously on a different conceptual level then the reader could be. For example implementation details are mentioned (for example the event_bits attribute in the generated HTML) while they have nothing to do with making you understand the API (writing an event callback class). Or the other way around, at places where a simple examples would do wonders there is only some broad goal description.
Since there are many other books on GWT, you are probably better of with another one.