A nice article, Stefan.
It reminded me of a story about Sergei Rachmaninov, one of the greatest pianists of the 20th Century, and renowned for his incredible technique.
He slowly learned the pieces he played, detail by detail. Abram Chasins told about visiting Rachmaninoff one day and stopping outside. Rachmaninoff "was practicing Chopin's Étude in thirds but at such a snail's pace that it took me a while to recognize it because so much time elapsed between each finger stroke and the next. Fascinated, I clocked this remarkable exhibition: 20 seconds per bar was his pace for almost an hour while I waited riveted to the spot, quite unable to ring the bell." Paradoxically, Rachmaninoff often sounded like he was improvising, though he actually was not. While his interpretations were comprised of mosaics of tiny details, when those mosaics came together in performance, they might, according to the tempo of the piece being played, fly past at great speed, giving the impression of instant thought.