Although it is nice to have multiple viewports, it's functionality is hindered by having so little control over what rendering method is being used on each. For example, when lighting your main window would be RT+AA using your render camera, whereas your second window would preferably be openGL using your perspective camera to easily move lights around. The current set up is buggy at best, the hotkey to tear off a window is also hidden very well, this could be more obvious.
thanks!