Don was a student of Hedwig Rosenthal, student and wife of Moriz Rosenthal, who was a student of Liszt. He was thus a connection to a now-nearly-lost pre-recording 19th-century musical tradition.
You can hear that tradition in the ferocious youthful technique in the Mephisto Waltz here, but even more in the exquisitely played Chopin Ballade:
https://innig.net/music/albums/betts-dimensions/
And that recording of the Beethoven 111, particularly the second movement? Unreal. It has the cosmos in it. Nobody plays that way anymore.