@Sascha Thanks a lot for your feedback, that’s very useful.
I hope you can join us next time! (I’ll post the new meetup thread in a few minutes) 
Maybe you could help us by reviewing what we prepared on http://www.xwiki.org/xwiki/bin/view/Compare/XWiki-vs-Confluence/ ? See this thread related to this: Comparing XWiki to MediaWiki and Confluence on xwiki.org Thanks!