To understand this, consider bars 185ff in the development section. Here, after a long passage where another theme dominated the scene, the main theme returns two times: first in d minor, then in B-flat major. How do the pianists play this passage?
- Kovacevich (https://youtu.be/MAZ8PA5_gVA?t=744) play the d-minor and the B-flat phrases quite in the same way.
- Brendel (https://youtu.be/TKy0Lyl4g-s?t=443) and Richter (https://youtu.be/ZbJtHzaFpBQ?t=983) play the second one much softer than the first, as if the B-flat phrase were a distant echo, or a timid answer, of the d-minor one.
- Uchida (https://youtu.be/l7cc2FD06FM?t=812) plays both occurrences very softly as if the composer wanted to remind the listener of the long-forgotten theme.
What I am trying to show here is that, apart from speed, there are many other subtle ways a pianist expresses what the composer meant. This kind of nuances can be very hard to spot, but adopting Richter's tempo makes easier to appreciate them.
How would it sound if other artists also played at a slower tempo? Can they even play at a lower tempo or that's Richter's specialty? Are there any other aspects of Richter's version besides the tempo I should be observing? I am not trying to play a devil's advocate, I am extremely curious as why I can't appreciate it as much as others.