I even worked with military simulators, and they themselves are segregated. The simpler ones use the "marketing" figures for secret stuff (the thing I specifically remember was range for air-to-air robots and turn capabilities etc), whereas some might use the real figures. I don't think even the most high fidelity simulators always use 100% accurate info, especially when it comes to radar stuff which is very very well guarded. Even though a lot of the code can be identical to the "flying code" for aircraft, there is still a lot of physical stuff that needs to be specifically modelled.

Given the actual harddisk size compared with advertised and how nutritional value and calories in supermarket foods are often misleading, it can be safe to say that the specification is hard to be believed.