I have tried getting version 2.3.0 to work with a Joomla 3.0.2 site I'm working on but have been unsuccessful. The component installs just fine, but in this version is unable to create a new sitemap. I have posted to the authors "Bugs" forum with the title of "Joomla 3 issue with XmapHelper class" to track this issue.
I look forward to seeing the issue resolved. Thanks for all the great work on this component.