Well, there's a little bit more to it than that; KDE and Gnome are software suites. In addition to the graphical layer running on top of X (KDE was built on Qt, Gnome on GTK, IFRC), both are complete with text editors, file browsers, web browsers, chat clients, configuration programs, etc. I've been using KDE since I switched from Gnome a few years ago. Before then, Gnome's interface and software complement weren't as professional as KDE's (might not be as professional now, either, but I wouldn't know); my computer could handle the extra load KDE had over Gnome, so I switched and haven't gone back.
For slower systems I use XFCE, and for ancient computers I use Windowmaker and Enlightenment. XFCE comes with a few extra programs in addition to the interface, and Windowmaker and Enlightenment are pretty much exclusively interface.
I would definitely say give KDE a try.