We're considering moving from trac to Atlassian Confluence as our knowledge base solution. ("We" are a growing IT consulting company, so most users are somewhat technical.)

There are many reasons we're looking for an alternative to trac: ACL, better wiki refactoring tools (Move/rename, Delete (retaining history), What links here, Attachments [change tracking], easier way to track changes (i.e. better "timeline" interface), etc.), "templates"/"macros", WYSIWYG/Word integration.

Confluence looks to be very nice from the feature list POV. But toying with it for a little I had the impression that its interface may seem somewhat confusing to the new users (and I recently saw a comment to that effect on SO). I hope that can be fixed by installing/creating a simpler skin, though.

If you've used Confluence, what are your thoughts on it?

• Do you agree it's not as easy to use as other software, can anything be done about it?
• What are its other shortcomings?
• Would you choose a different wiki if you had another chance?

[edit] my own experiences