Has anyone used G4JSF or GWT?

[SOSELLA]

Has anyone used G4JSF or GWT?  I have used Ajax4JSF extensively and want
to make my app even more rich and Web 2.0ish.  I have read Smirnov's
articles and agree with him that JSF is a good server-side solution for
navigation, etc.  G4JSF looks promising but wanted some feedback before
I invest time in it.  Are there other client-side UI frameworks using
AJAX features other than GWT?  Essentially, Web 2.0 like UI controls
that use Ajax4JSF rather than GWT?  Or am I missing something?