This is why I prefer Crunchbang Linux (or more generally, a good OpenBox based distro) to Xfce or Gnome 3 these days. I can freely switch between using a GTK app and its QT or other toolkit-based equivalent, assuming such equivalent exists, without the risk of breaking anything on the GUI side. With QT in particular becoming much more modular, I also don't end up with hundreds of megabytes of KDE bloat to support one 10MB app.