I use mostly pure GWT for my projects.
However you have to invest some time in creating custom widgets and style them for your needs.
In addition to the suggestions you already got, you could also check out Vaadin and Jboss Errai.
I really like Errai's UI templates which you can view in this screencast.
Vaading provides an appealing widget set and also is going to use GWT as a core in version 7.
Both (JBoss and Vaadin) are in the steering committee for future GWT developments.
