The answer is simple, both. The concept is that what a great performer needs is to tell us what is “behind the notes”.. It’s a fairly simple concept but many many younger generation pianists seem to miss this and instead go for the kill (meaning fingers running all over the keyboard.. faster, stronger.. as if it was some kind of Olympic Games of some sorts! )
if you are not a highly trained pianists, I would guess that it’s pretty impossible for you to figure out who is a real artist vs a showman/showwoman. Time will tell the difference.. none of us need to take chances and/or fight over who will be or will not be.. once again time will make that difference.
My natural instinct is to tell you (the reader): go to the people who have been recognized for at least 30+ years as masters (Horowitz, Brendel, Pollini, Argerich, Rubinstein etc,,, the list is fairly long) and you are pretty sure NOT to make a huge mistake.. it is possible that you may not react positively to some of them.. and it’s totally OKAY! no one loves every single painter, writer, sculpture, poet etc.. It becomes a matter of taste (who can be educated and later change).
Also, If you take any of those big name I mention before, you will notice that they (themselves) recognize and enormous change in their interpretations and maturity of how to play what is “behind the notes”. One of the most significant and striking example for me remain Glenn Gould and his emblematic versions of the “Goldberg Variations”. Between what he did when he was young (first recording) and the latest one, his tempo is almost twice as slow, and to me, far more interesting, profound and sublime than the first version (which was already pretty amazing). He is, for me, the living proof that going slower is the way rather than fingers running all over the keyboard.
Now, don't get me wrong, every Pros MUST have the abilities to have fingers able to run faster than fast all over the keyboard.. Not every piece require full throttle, but it’s easier to “hide” behind super fast tempos (it’s really tempi to be honest) and “wow” the audience because it IS impressive, then trying to reach the “behind the notes” and “wow” the audience with depth.. it’s a huge bet.. but to me that is worth doing.. and honestly since every single great pianists went through the same road and came out with the same conclusion (go slower and show what is behind the notes), therefore I would be shocked anyone could contradict me here!
I try, in my own way, to share and educate people who enjoy music and/or piano with my YouTube channel. I explain and perform all 32 Beethoven piano Sonatas one mvt. at a time. I would strongly suggest you (or anyone reading this) to watch my videos and learn how to go “behind the notes” and understand what can be heard and what shouldn’t. I approach the concept of speed (tempo the use the proper terminology) very often too.
I hope this text helps you, and I will be looking forward to your feedback.