Here is an email from Jorn at Tidal. I was trying to decide on which model would be the right fit for me. I gave them my info. and they type of music I listen to (pop/rock).
"The new Piano Cera is faster, more nuetral, and just the better speaker. It sounds like a small Sunray. BUT: The Tidal Piano is so magical in my world that I would not hesitate a second to choose it over the Cera. In fact, the Piano Cero will show you a U2 album is a lousy recording while the Piano Classic will still make music out of it and does not need crazy attention to the chain. My tip, the Piano it is."
Jorn.
Translation, if you only listen to rock, and that genre has a lot of lousy recordings, the Piano Classic is going to be the best fit. However, for classic or jazz or a wider range of music the Cera is the better fit.