Linux Mint 15 Cinnamon, ships with the latest version of the Cinnamon desktop environment. Like everything else, some users like Cinnamon, some others think its interface is outdated. I say, use anything you like. It’s part of what makes Free Software and the Free Software community what it is.
I’m currently using KDE on my main computer, but with the latest GNOME 3 (GNOME 3.8), I’m about to switch to a GNOME Shell desktop, customized using a couple of extensions. Freedom!