In looking at several recordings closely, I noticed that it seems like *nobody* really plays it as written.
What I mean is that in the broken octaves section (measures 13-20), as written, the melody is in triplets. The arpeggios are in septuplets (7 notes per quarter note). Thus, when the left hand plays the melody, the upper note of the octave should be played just after the right hand plays its second note on the descending part of the arpeggios.
What I see instead is that most pianists (including Hamelin and Lisitsa) will delay playing the right hand, such that the upper octave note by the left hand is instead played before the right hand plays the first note of those descending arpeggios, or between the first and second notes. This gives them enough time for the left hand to move back down and play the arpeggio notes after playing the melody notes. Which notes are played are as written, though (they do not redistribute the notes between hands during that section).
Lang Lang's rhythm is more accurate, but of course he does this by not switching hands at all -- his right hand plays the melody all the way through here, leaving the left hand to do the arpeggios. By consequence, although the melody is closer to triplets, the arpeggios aren't even either in timing or in volume.
I'm not exactly sure what to make of this. On one hand, I can only tell because I'm looking at them playing at 1/4 speed, while I can't really make it out at regular speed, so one can argue that it doesn't really matter if people can't really hear the difference. (Similarly, also everyone is uneven in the left hand when listening slowly to the 4:3 parts of Chopin's Fantaisie-Impromptu.) On the other hand, if people are arguing that it should be played as written, well, it doesn't seem like professional pianists do so, in order to play it at performance speed and have enough time for the left hand.
My thoughts are:
1. Switching hands is not only part of the technique of this piece, but also part of the visual flair. I'm surprised Lang Lang "unswitched" the melody because I would have expected him to be able to make the most of the theatrics with switching hands. (Instead, his theatrics are mostly with over-rubato-ing the phrasing.)
2. I'm a bit more undecided about redistributing notes in the arpeggios. It would be nice to play it as written, of course, but giving one more note to the right hand would make it much more feasible to keep the melody as triplets while playing the arpeggios with the correct timing. As for why Liszt wrote it that way (where the right hand isn't doing much when it could have played more notes, leaving the left hand to do most of the work), it could be as simple as he explicitly wanted people to work on fast left hand leaps (similar to La Campanella), or something more obscure as the publisher not wanting to typeset all those ledger lines below the treble clef when there's a perfectly good bass clef underneath it. What do people think?
P.S. Does anyone know what are Liszt's instructions regarding playing this piece? I've heard that the 3-2 fingering for the left hand for the melody in this section is part of Liszt's instructions, but I can't find anything about what else he wrote regarding this piece.
Hamelin's performance:
Lisitsa's performance:
Lang Lang's performance:
MIDI (to hear the timing "as written" so to speak):