"Beware of reviews that claim “unquestionably the most accurate [FM] ever created. A combination of science and art, the design team started with mathematical aerodynamic flight models created by the team's full-time aeronautical engineer.” Every flight simulation created in the modern world has an engineer, and most of them are very good. Some teams (IL-2 Sturmovik) have three or four qualified engineers."

"Microsoft uses table based models instead of full physics models. Table based models are generally more forgiving than full physics models. The novice flying IL-2 on full realism is going to have a very difficult time, whereas the novice flying CFS3 on “hard” settings will do better."  

http://www.cfspilots.50megs.com/lh/cfs3_review2.htm