I've written a long and rather enthusiastic review of Kubuntu 11.04 Natty Narwhal, with KDE 4.6 desktop, covering live session, installation and post-install usage; topics include Wireless, Samba sharing, look and feel, desktop effects, applications, Firefox 4 installation wizard, application desktop integration, package management, system stability, responsiveness, resource usage, battery life optimization, suspend & resume, extras, future outlook, and more. This ought to be pretty interesting.