Recomendation for speakers BEST for Piano?

I would contend that a time and phase coherent design is required to reproduce the piano accurately.

In addition, as someone pointed out above, the piano is a percussion instrument and requires not only speed, but great dynamics and FULL range as well. There are tons of overtones and undertones that resonate within the instrument while it's being played.

These requirements leave very few choices. I would agree that the larger (full range) Apogees such as the Divas and Scintillas do a tremendous job at capturing these elements. The other speakers that I recommend are the larger Thiels (3.6 and up).

I really do think that there's also something to the metal drivers. I've NEVER heard a soft-dome tweeter believably reproduce the piano.

Maybe it's just me, but I've never heard large Thiel speakers (and this includes 2.3) that sounded anywhere near as coherent and musical, especially in the midrange, as the 1.5.

Listening to Arturo Benedetti Michelangeli's live recording of Chopin's piano sonata no. 2 (from 1952 no less) was an eargasmic experience I shall not soon forget.

Gullahisland points out that there are many overtones resonating when a piano is played. To discern the sonic character and personality of the instrument, the timing has to be dead on and the speaker has to recreate the reverberant sound field to endow the reproduced sound with the vibrancy and harmonic richness you immediately recognize as live sound. Additionally, accurately reproducing the size and sound of the body of the instrument and conveying venue information (hall sound) well requires good extended bass response which must blend seamlessly. There are few loudspeakers which successfully do all of this. In my experience and opinion full range dipoles do it best.

Old apogee speakers, kharma, avalon, and audio note can all be fantastic on piano...

Well, it would seem that the choice of speakers alone is out of context with the rest of one's system. Yes, Quads can sound great. I've listened to them powered by Naim separates, and they are wonderful. I've also listened to them powered by a Berning set-up, and they did not sound nearly so good. My Cabasse, pushed by a Plinius integrated, reproduce piano fantastically.