Disco Dingo one day in... so far, so good. Dash to dock seemed to go pear-shaped to start with - even after upgrading it - but a reboot fixed that luckily. New icons are great, UI looks a bit cleaner/fresher. Really liking the notification icons (e.g. number of new mails) in the dock (users of other operating systems, who have had this for ages, can start laughing now).