Just curious, even though it's none of my business...
Why do you want to turn Retina off and have the display look non-Retina?
more working space? less processing? i know if you put it at 1920x1200. its actually doing double the work going 3840x2400.
i used to have it at 1920x 1200, but i found that the regular "best for retina" setting was the best.