To me even the very highest end digital pianos still sound digital, but they are close enough and the benefits of digital outweigh what you might sacrifice in sound for most people.

I've noticed there is also fierce debate between digital pianos that are based on sampled sounds versus modeled. I believe most Roland digitals are modeled with Fourier series, while all/most of their competitors are sampled (not sure about Nord). That said Pianoteq is a popular after market VST that will bring a very convincing top tier modeled sound to even a low end digital piano.