If you’re considering using GWT to do web development, here are some of the issues we’ve encountered – sufficiently difficult and frustrating that the organization has decided to abandon GWT and return back to Spring MVC as the web tier.

1. Difficult to integrate into SEO – I didn’t see this directly (because I am not focused on SEO) but apparently all that javascript makes indexing the pages much, much harder
2. Unit Testing – the design of GWT widgets makes it very difficult to write unit tests using anything other than the “built-in” GWTUnitTest, which isn’t helpful for our situation (we need the output in a particular format for tracking purposes).    So essentially we didn’t unit test our GWT widgets much at all
3. Which means our code coverage was very low, and it requires a lot of “jumping through hoops” to get the code coverage to even modest (40%) levels.
4. Most people can’t seem to get used to the programmatic paradigm – horizontalPanel.add( verticalPanel3 );    It’s very hard to debug programmatic panel creation, and it’s easy to get something wrong, and not realize it until you’ve compiled and built everything.   I know they’ve added some XML-based visual building recently, but unfortunately we’re working with legacy code
5. Compilation time – it seems to take a _long_ time to build all the locals and browser variants, and going in and restricting the list of locals and browsers made it harder to track down bugs

This was a large organization, with a lot of resources and fairly smart people, and GWT just simply defeated them – they could not figure out a way to get it to behave in a way that their organization could absorb.    I’m sure all the GWT experts are sneering at our “pathetic lack of skillz” and that’s fine (whatever!), but for me, I don’t plan on recommending GWT to any of my clients.