KDE apps, including Kontact, force me to use the KDE look and feel,
pretty much ignore the GNOME settings I am used to. So KDE is just as
well forcing _its_ model on you, just a different model.
Well, if you use the good old Bluecurve theme (not Clearlooks which has no KDE
equivalent) in both Qt/KDE and GTK+/GNOME, you'll have to look very closely to
even notice the difference. It's good enough for me. (I run KDE, but GTK+ apps
integrate very well with my desktop.)