Overall I've been very happy with the versions of Joomla 3. Here's a brief highlight of items I like, and perhaps a few I don't:

  • The Update Manager is a vast improvement over previous update methods. I administer a site using a "competing" CMS, and it still relies upon file management for updating software. It's barbaric every time I lay my hands on it. "Where's my rock knife to run the FTP?"

  • Another big step is Version Management, for salvaging previous article iterations. For the sake of your users, activate this tool, and you might find yourself using it as well. 

  • This isn't my area of expertise, but the eco-system for both quality free and commercial extensions seems healthy.