I don't know where this mod has been all my life. But I gotta say, it lifted KSP to a whole new level.
As you can see in these images, Wind Tunnel showed a peak in the envelope at 12,912 m at 281 m/s. Actual performance was pretty close, though I was able to exceed the expected ceiling by some margin.
I find I get the most accurate results when the aircraft is oriented in the SPH with the main lifting foil pointed directly at the horizon. Aircraft with a main wing that has plenty of incidence angle will appear to hang nose down.