The thing I like most about XWiki is the possibility to change the basic templates by using velocity. I did some fine tuning directly in the SnipSnap JSPs so it was no big deal for me. But I know how to read JSP code and found out how to package and deploy SnipSnap. But perhaps not everybody considers this kind of work "fun".
And when I decided to use SnipSnap (approx. two weeks ago) the look and feel of XWiki was awful and didn't even work in Firefox. That has changed. But too late.