@CyberGene You are right on the motion of the Viennese action. So, it's not just dynamic control the action is responsible for, but in this case also partly the timbre.
Voicing is absolutely very effective in changing the tone. If not more effective.
It's just that, in our case, the action is partly responsible too. And upon finding that out, we thought it would be nice to share.
To quote Alfred Dolge, who wrote "Pianos And Their Makers" in 1911:
'Meantime, Johann Andreas Stein, and his talented daughter, Nannette Stein-Streicher, who was not only an excellent musician, but also a thoroughly practical and scientific piano maker, had improved the Schroter action so materially that the grand pianos made by them from 1780 on, were preferred by Mozart, Beethoven and other masters, perhaps mainly for the reason that this action not only had a more elastic touch than the Christofori English action, but that it produced a more sympathetic tone, reminding of the clavichord tone, which all the great players of that period admired so much. This sympathetic tone could only be produced with the Vienna action, because the hammer, when striking, would to some extent graze or draw along the string, while the more forceful attack of the English "jack" action is a straight and direct percussion. These two elements, the pleasant light elastic touch, and the charming musical quality of tone, assured the Vienna grand pianos (flügel) supremacy in Germany, Austria and Italy for many years.'