The "view differences" feature is very nice. I think it should be possible to check the differences between any two revisions, as it is done in mediawiki (see for example here).
Include page name and category information in the comparison. If the page is renamed or categorized, the comparison between the last and previous revisions does not show any changes.
This last suggestion was implemented in version 0.35.
You need to download the GXwiki Diff Utility KB to get this feature locally in your installation.