For me too, the most important quality of a simulator is the flight model of its aircraft and rotorcraft.
With P3D I've never been disappointed.
Its latest version, P3DV5.4, is very mature, and with it I can enjoy a huge number of aircraft and rotorcraft
with VFR or IFR flight qualities that I can't find on other simulators or... Xbox games.
However, I'll stop at this version 5.4, as I've unfortunately learned
that my great Lorby SI FireFighterX addon is definitively incompatible with P3Dv6.