Nik
For years I used various piano sample libraries (Ivory, East West, etc and I liked VI Labs Ravenscroft the best) and within the past 6 months discovered Pianoteq 8.
P8 has totally floored me with the adjustability.
It can be overwhelming but my advice for any getting started is this:
-Start with any basic factory preset that sounds overall best to you.
-turn off all the preset's EQ and effects
-switch to binaural mode
So now you are hearing basically the pure model that the French geniuses built for us!
-fiddle with a few parameters to learn how they impact the fundamental sound
But be warned--huge rabbit hole risk for hours of time obsessing over sound design. You were warned, at least.
However, for simplicity my current process is starting with a factory preset and then all I do is play with the microphone settings.
By adjusting only the mic settings I can get almost any tone imaginable.
The mic part is the most amazing part of P8