Top three classical period pianists

[bwv 1080]

What about JS Bach?

did Bach ever play a piano?

[bwv 1080]

That was not my point, but yes, Gottfried Silbermann's

Ok but Bach died before the Classical period began

[amw]

I'm fairly sure CPE Bach was already writing music before 1750

[Todd]

Michael Endres
Andras Schiff
Christian Zacharias

[Ken B]

did Bach ever play a piano?

Yes! On one occasion I believe. An early version.

[Jo498]

Mozart claimed Clementi's playing was technically not up to snuff, so if one believes him (could have been just mean-spirited, if very entertaining griping about a competitor) one may wish to substitute Czerny or Dussek...

I seriously suspect that Mozart realized that Clementi was technically superior or in any case "more modern" player and that he was both jealous and maybe also disliked the "new style".
There is also a remark from the young Beethoven that he disliked Mozart's "detaché" and less cantabile playing (while he of course admired Mozart as a composer unconditionally) and I think Beethoven spoke well of Clementi's playing but I might be confusing of conflating thing. In any case there seems to have been a change of taste involved that was not directly dependent on technical prowess.
Czerny and Dussek are younger, so probably they were better and Czerny is of course a Godfather of later piano playing but as far as I recall Clementi was recognized as the pioneer of the then (early 1800s) modern playing style.

[trazom]

I seriously suspect that Mozart realized that Clementi was technically superior or in any case "more modern" player and that he was both jealous and maybe also disliked the "new style".
There is also a remark from the young Beethoven that he disliked Mozart's "detaché" and less cantabile playing (while he of course admired Mozart as a composer unconditionally) and I think Beethoven spoke well of Clementi's playing but I might be confusing of conflating thing. In any case there seems to have been a change of taste involved that was not directly dependent on technical prowess.
Czerny and Dussek are younger, so probably they were better and Czerny is of course a Godfather of later piano playing but as far as I recall Clementi was recognized as the pioneer of the then (early 1800s) modern playing style.

That's what Czerny claims Beethoven told him, that Mozart's playing was too staccato, but Ferdinand Ries also said Beethoven regretted he never heard Mozart play the piano. I don't remember reading about Beethoven regarding Clementi's playing, only his preference for Clementi's sonatas. Mozart wouldn't have had any reason to be jealous of Clementi's playing since Mozart's reputation as a pianist and improviser was already firmly established in Vienna and, for the most part, his style of playing was preferred by musicians and connoisseurs, at least, according to Dittersdorf's reported exchange with the Emperor. Mozart's preeminence as a pianist is something that stayed with him throughout his life and seems like an aspect that's downplayed these days in respect to his accomplishments as a composer.  The success of the concert he gave in Prague in 1787 performing variations on "non piu andrai" for half an hour is one of the most-cited and the effects it had on Stepanek, Niemetschek, and the audience doesn't give the impression of Mozart as pianistically rusty or unpracticed.