One thing that I forgot to mention, regarding X-Plane's flight dynamics, is that they depend on the shape of the aircraft in order to calculate the aerodynamic forces on the aircraft. This is another reason why I think that Captain Sim's aircraft are perfect for X-Plane because their exterior models appear to be flawless (707, 737 and 777). This means that, since the shapes of Captain Sim's aircraft (707, 737 and 777) are very accurate, their flight characteristics will be simulated to be very accurate, as well.