An effective simulation flight model is more about matching pilot workload than it is about matching QTG plots. Unfortunately, the regulatory bodies like the FAA and EASA insist on flight models that match real aircraft data at the expense of matching workload.
In reality, a sim will probably never be an identical match to the actual aircraft, even if it had a flight model that matched the actual aircraft in every possible way. Too many cues are missing from the simulation environment, especially for small aircraft that are flown mostly in a VFR manner... and this is often why a lot of experienced pilots walk away from a sim disgusted.
But sims certainly can be used for learning and improving manual flying skills. The US Navy is doing it now... but they were smart and decided to go with unqualified devices that had flight models installed that matched the workload of the real aircraft rather than matching dots on a QTG plot.