I have once tested an electric piano that was using binaural audio (so you have to use headphones for the experience). I have to say, this was the most realistic sound I have heard from an electric piano, because spatially it made sense. I had the impression that the sound was coming from the piano, not from my headphones, and this made a huge difference.

However, the feel (the touch) of a grand piano is still miles ahead of modern full fledged electric pianos, and I would prefer any day to play on a grand piano than an electric with all its gimmicks.