Somewhere in this thread I saw a quest for student input. I came back to "piano" after a 30 year absence as a self-taught student. I inherited a keyboard with shallow light keys, no touch sensitivity. I took the occasional piano lesson with my violin teacher. To answer your question, Stretto, having played a lot when young, I could make the transition, but I would have to get the feeling of the piano keys under my fingers for half a minute. I would notice which fingers were heavier than other fingers, and could do nothing about it once I got home. I centred my learning on tempo, keys, transposing, because that's all that I could do. I tried playing at a student concert, practising on a rented piano two days before and my first quiet notes came out senza voce, total silence to the sight of softly gliding fingers. I would think that practicing on a keyboard teaches you how to play the keyboard. It is a different instrument, is it not?
Since half a year I have a used touch sensitive electric piano of good quality. I could afford it, and I can finally do something about dynamics, pedal, and keys that are deep enough, heavy enough, and show some response. When I tried it out, it stood next to a real piano which was not for sale. I went back and forth for an hour. The sound is audience-impressing: grand piano reverberations. I found it disturbing because there was something false about the digital adjustments. There is an after-echo happening at the back of the sound board of a real piano, and that after-echo was programmed into my piano, but it happened two dimensionally and this bothered me too. Just at a time when as a violin student I am becoming sensitive and aware of nuances of sound, I had to close myself off from the full spectrum of sounds of this instrument. This also goes for touch and responsiveness. Yet it is a good instrument - it gives that "instant impressive sound" which overwhelms, grand piano and all. It is part of our new world that knows no subtleties and shades, where the senses have been dulled and people want to sound instantaneously good.
Dr. Leland writes about touch, and I think I know what he means. I was feeling for the shades of sound, the interaction and balances of keys that would allow the hammers to strike in a thousand ways. It's not there in the digital. There is no physical interaction - again, if you are already sensitive to instruments, you become desensitized because there is nothing to respond to or that responds. Analogue is infinite: digital is finite. Besides, some pianist's touch has been recorded into this piano. His sound comes out, not mine. His touch, on an acoustic piano, has been recorded, tweaked, and put into my piano. That bothers me. I'm jealous. I want my sound to be my own sound, not someone else's.
I came on this board asking for help before a student performance. In that performance, on a real piano, I was able to do something fantastic with the final chord, which was played pianissimo and was meant to die to nothingness. I could raise the pedal for a dramatic brief pause, descend the pedal, gently press my five keys "just so" while feeling out the balances (as Dr. Leland describes) "just so", then keep the pedal depressed. The other strings would have their various sympathetic rings. The digital piano could mimic that part, and the annoying "backboard mimic" isn't there for quiet notes. But the last part could not be imitated by the digital. In this I released the pedal, kept the keys depressed, and now only those five sets of strings kept up their vibrations, sympathetic and all (since they were chords) and interacted according to physics. The effect was a fading away that changed colour as the pedal was released but the keys held down. Doing the same thing with the digital did one thing. The sound stops immediately. There is no colour and there are no shades.
I find the lack of interaction and shades on a physical, sensual level between the instrument and the sound to be dulling to the senses and imagination, and even creating some tension. I think this is because when we interact with something, our bodies respond more automatically or naturally. And I don't like instant nice sounds. I want to work for my sound, and create it myself.
But I'm not a child though I am a student. What about children? I remember exploring textures of instruments. One of my children is en route toward becoming a professional musician, and as a child he was exploring textures and sounds in all their nuances, imitating what he heard, seeing what kinds of sounds could be produced - forever banging, listening, trying. Are these explorations and discoveries lost on digital instruments? Is it about producing a melody and the right notes, and only that? What is music? My earliest memory of musical instruments is about melody, of course, but also the tones and sounds themselves. They spoke to me personally. And everywhere there is physical touch, responsiveness, even the quirks of an acoustic instrument giving it personality. If children's senses are more alive than those of an adult, do these sensations matter?
I still have my keyboard and it has its uses. Switching from piano to organ or flute is a fast way of catching uneven notes, and hearing a melody from a different angle. I think it can hook up to the computer for composition. It is portable for practising away from home anywhere that has electricity.
The big advantage of the electric piano is that I can plug in ear phones and practice in the dead of night.
I suppose the best of all worlds would be to have both. I would not want to stay forever with only a digital piano. I have already heard the comment of one pianist hearing me play say instantly, "I can hear that you don't have an acoustic piano. It is limiting your playing." and I could hear that myself.