GWT in enterprise

I have been working lately into integrating GWT in our products.
The rationale behind this is that GWT is offering me the same work style on web applications as Swing for rich clients and it cleanly separates the views from the actual processing tasks using JSON RPC. I have considered also Tapestry, Wicket and JSF for the same task - but all those frameworks - although sound and very mature were forcing me to use a Java server side framework.
In my case this was sometimes a little bit of overhead. GWT on the other hand is very server agnostic and I have successfuly integrated it both with Java servers side as well as with Python/modPython. I know that JSF has more features when it comes to be compared side by side with GWT, but the latter one scores better in terms of application responsiveness and it is starting toa have a complete ecosystem around it (gwt-ext for example).