I'm getting mouse shoulder-itis (even had to put my wife's bursitis shoulder ice pack on the other evening!) from doing test renders in Carrara. I appreciate being able to do them but my mouse is definitely getting a workout. Maybe there could at least be a control key sequence to say "test render the same area I test rendered last time". You can do Ctrl-R but then you switch over to the Render Room and have to wait a bit for the full render. C4D handles this nicely in that you can Ctrl-R render from any view and at least for simple scenes the renderer is very fast (no need for area rendering at all).