[lucas_codes]

I'm a professional musician but not on piano, and even I can tell the difference.

While it may be true that velocity is the only variable, it's not a physics problem. As a player you can't choose the instantaneous velocity for the note, and the note is played at the same time or immediately before/after other notes, which all adds more variables to the touch and the movement of the musician.

Therefore the whole action matters, including how the key travels, the decoupling point, the resistance of the multiple parts of the action, the rebound... etc

It's interesting you're happy to disregard pianists opinions on the matter. Perhaps you think experts are too mired in tradition to see the truth? That may be true sometimes, but you also don't have the same grasp of what's involved as they do.

[jojobas]

You forgot the two words: blind test.

I know for a fact that experts can't tell Stradivari from modern high quality violins, can't tell if two glasses of wine are from across the world of each other or from the same bottle, rumours are they can't tell whether they're listening to a recording or live string quartet.

https://www.science.org/content/article/million-dollar-strad...

https://www.theguardian.com/lifeandstyle/2013/jun/23/wine-ta...

There is quite some variation between real piano actions of grand vs upright, 18th century and modern, German vs French vs English action etc. There's also no magic about either of them and no fundamental reason why an electronically coupled action couldn't exactly mimic them.

[lucas_codes]

I don't know about wine, but those violinists were asked which instrument they preferred, not which was a Strad.

I don't see how that or a blind test is relevant to what I wrote anyway? Except for a cheap dismissal.

[rjvs]

Likewise for narrower keys on the piano, surely.