The Camp Wiki has reached beta quality now. Many people have already signed up already. I am looking forward to more content coming in soon.
The experience with TWiki is mixed, but still basically positive. It is powerful, but slow. It is flexible but it‘s SmallTalk-like distribution (pumping out an image of mixed runtime/developer/default content) doesn‘t come without its price.
I have the feeling that progress within the community is strong and the appearance of a new Installer gives me the impression that community is well aware of their current limitations.
On the other hand, I also like the stripped-down super-simple and elegant PhpWiki-based Dylan Language WikiWikiWeb. It beautyfully matches the straightforward elegance of Dylan itself.