expressive velocity curve =/= realistic curve

I own a VPC1 and used the integrated pianoteq curve until recently. I visited a piano dealer and tested (smaller) Yamaha, Kawai, Steinway and Bluethner grand pianos.
I realized that I was playing too loud, because of the attack I got used to with the VPC1. I needed to be way more lighter, to get a p or pp.
Especially the Steinway was very different. Smooth scale runs were easier due too less unwanted explosiveness.
So I created an own curve, which lets me work harder (=lighter) to play more quiet. Too low velocitys shouldn't give sound at all (I think <=2).
Also the velocity curve shouldn't be too explosive in higher velocities. A fff should be very hard to achieve.

So I came up with a curve, which looks like it sacrifices expressiveness.
But I think its way more realistic. The sound is more overwhelming and the virtual piano seems more like something grand you can only tame with a light touch.
Same dynamic range is still possible.
Mezzoforte or mezzopiano scale runs are the only things which seem more easy to pull off cleanly.

What do you mean, is an expressive curve like the integrated pianoteq-curve never realistic?