IMHO the layout of example for a4j:region should be altered to achieve that:
1. the echo panels are below each other
2. when something is submitted to the second echo panel than the label "Echo panel" is not moved, and remains at initial position, which is not the case now, since it is centered
3. when long text is submitted it should not exceed the white part of the page
Currently it uses h:panelGrid for layout, maybe it should be worth to use rich:panel without header in some way, this will also achieve that long texts do not exceed white part. This is the same for all demos which renders the submitted text from input.