Best speaker/system piano concerts

Without going into wordy sonic descriptors I would go with Focals you pick the model based on budget along with Pass Labs amplification preferable something in the XA series.  

Chuck 

Here you go:

https://carusopianos.com/browse-pianos/player-pianos

Best reproduction of piano sound.

Kalali nailed it all of those will sound more like a Piano and be more beneficial (physically & mentally)  then sitting and listening to recorded music.

I play a Mason & Hamlin myself (Classical Piano) predominantly Chopin. 

Chuck 

@wolf_garcia

You write, "Great piano reproduction by any system becomes evident when you notice that all recorded pianos sound somewhat different from each other."

I think that you are setting the bar far too low for what the OP has in mind. Any decent system can differentiate a Yamaha and a Steinway Concert. What I meant by writing, "doesn’t quite sound like the grand upstairs," is not a reference to the timbral differences but the percussive attack, which is a property of the generic instrument, and is very hard to reproduce.

That requires great speed everywhere in the chain, and that requires subtlety of electronic design.

Speed isn't an audio term I pay much attention to as it's somewhat meaningless...subtlety in design? Does that mean careful soldering? A great sounding system puts the recording into the air relatively unscathed, so the recording is where the differences should be, and not in the system necessarily. Also if "decent systems" can differentiate between a Yamaha and Steinway it makes me wonder how many listeners can do that, or if that matters...the reference for the "absolute sound" for pianos is interesting to me as I've refined my piano miking technique over decades mostly by working with so many brilliant artists, and many want specific things requiring different setups. Miking for recording is different as level and sound leakage are issues primarily with louder live reinforced stuff...and is the sound one wants supposed to accentuate the "percussive attack" (which I feel is in the hands of the player), or the overall sound as heard by someone other than the musician?..i.e. somebody near the piano hearing the cumulative tone as it resolves the various elements of the instrument. I've heard recording where you can hear the mechanical elements of a piano here and there and that's somewhat disturbing, although the performance and passion of the music is all that matters really, otherwise the audioiphile critical nitpicking can harsh your mellow, so to speak.