As you would expect of a product aimed squarely at the enterprise market, security functionality is well implemented. The editing experience is also richer now, mainly because of the additional power that has been brought right into the editing window. Without leaving this you can add images, attach files, perform batch renaming of pages and even perform searches for page links. All pages, comments, blogs and attachments within any wiki are searchable.
We particularly like the whole spaces model, which allows for multiple linked wikis, and the news function, which enables you to have a blog in every one.