ExtJs Vs Ext GWT Vs SmartGWT

Question

I am going to start a new application which mainly consist NavigationPane, Grid, Toolbar. Layout should look like this demo page http://www.gwt-ext.com/demo/

I am qu

Answer 1

The GWT-Ext main page now says

"GWT-Ext is no longer under active development and has been superseded by Smart GWT. Assistance will be provided to existing users of GWT-Ext looking to migrate to Smart GWT."

so why would anyone use it?