>It's just that the default settings – only one panel (at the top), ugly blue theme & background image – are not very appealing and feel dated.

I used to run exclusively Linux distros, but then switched to OS X around 2008. Recently, I installed the Xubuntu Desktop and I felt that dated feeling you write about. My thought was, "Wow this hasn't changed" Even if it has changed, I couldn't tell at a glance. That's good in one way, but bad in a lot of others.