WP 6.6. brings nicer looks in the back-end
For fans of the new WP editor (FSE) there are some enhancements in the UI. All the pagebuilder lovers will almost see no changes in their workflow.
As for now there are some issues where WP 6.6. affects the CSS styles sheets of ‘traditional themes’. As a rule of thumb SitePatrol.net upgrades only to WP versions with a point-1 release (WP 6.6.1 or higher).
Source: wordpress.com
Release overview: https://wordpress.org/download/releases/