Not sure if you realize, but rather than windowed mode and re-sizing the window to fit 2 monitors…you can use nvidia surround, which will set both monitors as one large monitor within windows. you can then just use full screen and use the new extended res in the sim…I guess, with only 2 instead of 3, it will depend how you have your monitors positioned as to how well this will work though.
Using either of these methods will likely give you better frame rate/performance…but both are inferior in my opinion to using separate views from the experimental section. With the views, you can make things look very nice and in correct proportions, but with one big monitor (or1 window spanning 2 monitors), you get a lot of warping and stretching at the edges…again, I suppose it depends on how you have your monitors set up though.