Hey Geoff,
Unfortunately CComment4 doesn't use all the power of the new joomla framework. In CComment5 you will have the "Options" button and you will be able to select which group to do what.
If you don't want to wait
you will need to make some file hacking
in administrator/components/com_comment/comment.php
right after:
defined('_JEXEC') or die('Direct Access to this location is not allowed.');
add this code:
// Access check.
if (!JFactory::getUser()->authorise('core.manage', 'com_content')) {
return JError::raiseWarning(404, JText::_('JERROR_ALERTNOAUTHOR'));
}
This code is basically the same as in com_content. So users that have access to com_content will also be able to access the comments.
Hope that this helps!
Cheers,
Daniel