I might add that in terms of touch, tone, and dynamic range are concerned, it is a fantastic experience to play a historic instrument (or replica) if you can. I know, it's not practical for most to actually own such an instrument, but even listening to one live can alter one's perception of a piece. Pianos once had much, much lighter actions (Viennese style pianos being the most light and responsive from what I understand), different tonal qualities, and dynamic abilities. Playing Mozart, for example, on a Viennese action grand from that period is amazing and eye-opening. It really makes you realize how different our pianos are today, and how ill-suited they can be to certain pieces or passages. Moonlight sonata - that beautiful first movement - becomes an incredibly nuanced whispered poem on a piano from that era... truly truly amazing.
Just a thought or two...
JH