Just some more FYI...X-Plane uses an actual physics model like what aerospace engineers use to develop new aircraft. In fact X-Plane is used by engineers to develop aircraft. So basically the performance is partially based on the shape of the aircraft, im sure power, & weight are factored in with a confg. As you know an air-foil  gives an ac lift. Without it in XPlane you got a odd shaped ground vehicle.You can feel the difference in each individual aircraft

Here are some shots showing how the aircraft reacts to the environment...my guess is the green lines represent lift....