Hi Jay, Roger Kitain has explained a little the differences between @form and @all on JSF issue tracker .
But it doesn't give answer for what application is @all handy.
I added the issue to http://community.jboss.org/wiki/RichFacesJSF21ProposedEnhancementsandIssues as spec clarification.
ok, thanks for following up, I agree it is not the best explanation :-(
We'll follow up with other issues, and see if we can get clarification. In the mean time it might be good to try this with myfaces if possible.
IIRC, the difference is in view metadata (request parameters) processing.