I think that KDE has a lot of potential.
Unlike GNOME, KDE has 3 workspaces, each for a different kind of device - Desktop for PC, Netbook for netbooks, Active for tablets. It doesn't try to make desktops look like touch devices like GNOME. KDE Desktop still remains very traditional, yet with many exciting features and a beautiful look. For touchscreen devices, Plasma Active does a good job. And the Netbook interface is very useful on my 12.1' laptop - everything goes fullscreen.
KDE is very customizable, it has almost everything you would imagine. For example, KDE even has a global menu, an HUD-like search feature, a Dash and an Icon-only Task Manager (which can be set to function as a dock or a Unity Launcher)! Qt themes are color-changeable. KWin is like a second Compiz, with wobbly windows and such. The calendar has Gregorian, Julian, Coptic, Japanese, Thai... systems, and even has a Common Era option for atheists
However, having used GNOME for a long time, I was lost in the System Settings. Sometimes I wish KDE were simpler, or at least has a "simple mode". I would definitely use KDE if it were lighter, less buggy and had more GTK-compatible themes...