The worst part about controls inside the titlebar is things like Firefox and Chromium which implement their own decorations and window design with the tabs ending up in 95% of your draggable titlebar area, so you often end up moving the tab instead of moving the window. I'm not sure who will blink first with the lousy design situation, but the users are paying the price. (Honestly browsers just need to change this...Gnome is most people's default and they've shown themselves to be pretty damned stubborn)