I like to use multiple cameras in a complex scene so I can bounce around the scene quickly while leaving the rendering camera alone. (I often call it the RenderCam and reset the Render room settings accordingly early on in my setup of the file to minimize problems later.) I also find that choosing the Director's Camera, then using the goto... option to jump to one of my cams works well. Then I can use the camera options to move the Director's camera around an object, while leaving my 'preset' cameras in place.