pipAT
Given C4 the middle C, I've found annoying D6 in many sampled pianos. Maybe it's the issue of my humble speakers. I tried to switch left channel to right channel. The distortion seems to disappear. Not all virtual pianos provide player and audience flap options. I have to do manually and exhange the position of my speakers as well. So, again that's bottom on the left and top register on the right. I only let Garritan CFX always sit in audience position ‘cause I feel that's more natural for my ears.
One thing left, VSL has a "Body" percent option on UI. Maybe that could fix a little bit.