They're different beasts. In fact, they're different enough that they have their own niches. Gnome is the boring, serious, stop-fiddling-and-get-things-done UI. KDE is the quirky uncle that lets you play with his porcelain figures.

These days I prefer KDE, and I accept quirky behavior like losing a widget panel from external monitor 1 if you unplug external monitor 2, because I know it will come back after reboot/relogin. In exchange for that, I get different wallpapers for each monitor, custom/extra panels, several alternatives for application menus and taskbars, lots of widgets, and a few small QOL perks I can't remember right now.

If KDE becomes too quirky, I can always go back to Gnome, but right now I'm happy with KDE.