We are banding the word flight simulator around too loosely.
A flight simulator is what its wording suggests ie anything from the aerobatic pilot using his hand to paint pictures in his mind of the manouvres he will carry out in a competition to an all dancing full blown 3 axis simulator used by the big boys.
MSFS always worked best and was most realistic on autopilot and in the IFR/IMC invironment.
For handflying the models were far too twitchy acted like a puppet on a string had literally no accurate control forces or changes in stick rudder movements and were unable to model aircraft behaviour out of the box of normal operations.
One flight dynamics Guru Rob Young of RealAir Simulations played with the FDE and with a mass of tricks simulated spinning and created a better "feel"
The visuals and weather are pretty well modelled but for total immersion not as good as the old flight Unlimited which although not graphically brilliant was dynamically so.
The problems with it was that MSFS was everything to everybody. All the addons loaded the graphics and brought the sim to a stuttering halt.
MS dropped out and who knows how long the sim will go before going out of date like the other sims Pro Pilot, Fllight Unlimited etc. Only X Plane is in current production but I never used that one.
Pace