GWT's RequestFactory feature particularly stands out as a huge productivity win for CRUD apps. Also, many of the weaknesses commonly associated with Java are diminished now that Google's excellent Java libraries (Guava, Guice) have become more widespread (with GWT versions also avaiable).
But I think people try GWT once, realize that the built-in widgets and panels look terrible and never look back. But some of the features that they don't get to trying are the features that really makes GWT worth using (the EventBus, RequestFactory, UiBinder, the excellent localization support, etc.).
GWT also doesn't preclude using any other JavaScript libraries. JSNI (writing native JavaScript within GWT Java source) is relatively easy -- I don't think it is uncommon to pull in JQuery in a GWT app for its effects, for example.
But I think people try GWT once, realize that the built-in widgets and panels look terrible and never look back. But some of the features that they don't get to trying are the features that really makes GWT worth using (the EventBus, RequestFactory, UiBinder, the excellent localization support, etc.).
GWT also doesn't preclude using any other JavaScript libraries. JSNI (writing native JavaScript within GWT Java source) is relatively easy -- I don't think it is uncommon to pull in JQuery in a GWT app for its effects, for example.