I know he does (and I note here that you refrain from comparisons with Grante or Hatto, or with any of the other pianists who have only performed/recorded some rather than all of these works - Hobson, Béroff, Berezovsky, etc. - in this particular regard), but the sheer fact of this additional velocity (in those cases where it applies) still does not of itself make his performances of these pieces any more of a viable spectator sport to observe with the eye. Naturally, pianists with some understanding of all that is involved in preparing and presenting these pieces will be more impressed by Libetta's achievement with them than those who do not have that knowledge, but my point here is that these works have few examples of extreme leaps, rapid octaves and the other kinds of requirement whose presentation is more obvious to the semi-trained eye, their principal challenges being instead in the sensitive balancing and articulation of multiple linear layers and other issues more closely related to matters of hand-eye co-ordination; furthermore, they are less amenable to physically demonstrative playing in any case.
true, they are the primary challenges in most of the godowsky studies, atheletic displays take a back seat.
there are 53 of them though..., at least the op10/1version 1, 10/2 - both versions, and many of the fast paced ones offer an 'atheletic challenge'.
the 10/1 version doesnt sound as good when played super fast though, it loses the grandeur, but it can still be used an an arpeggio challenge for both hands...
certain LH etudes like the 10/4 and 10/12 really do IMO sound better taken at a tempo similar to the original, this is VERY challenging, and all the moreso because the pianist has to maintain the clarity of the various simultanious lines whilst keeping the breakneck pace.
this is where i feel hamelin is lacking in some of the etudes...he lacks the fire, he has the clarity, plays all the notes, but not fast enough to produce the fire that libetta does with his 10/4 LH rendition in particular.
berezovsky is very impressive too, but his LH dexterity isnt quite at the level of libetta, as i have observed.
What you haven't yet told us (although, to be fair, you've not yet been asked to do so in as many words), is whether you might consider certain passages in OC as equally useful determinants of a pianist's abilities in extended examples of rapid single-note passagework were your practical familiarity with them as great as it is with Chopin's Op. 10 No. 2; perhaps you might feel inclined to enlighten us on that, if you are able.
im not intimately familiar with the piece, of course there are examples of rapid single-note passagework, and the OC covers just about every pianistic figuration known to man.
ive noticed there are brief parts with a figuration similar to that of 10/2, but it doesnt look as though they are meant to be played extremely fast.
in any case, ANY passage in any piececan be used to compare the mechanism of a pianist in that particular figuration.
the question IS....which figuration provides the most efficient means of determening the 'raw mechanical ability' of a pianist, if played with the utmost velocity, accuracy and control.
ANY figuration will provide some insight, to some degree, but some provide more obvious results than others, some are more 'pure'.
chopin etudes are precisely this, they provide sustained essays running with certain pianistic figurations, thus - the mechanism of the player can be measured in terms of both basic speed, and endurance - due to the fact the figuration is sustained - varied upon, but still using the same finger groupings.
10/2 is not simple single note runs....i dont know where you got this impression from.
10/1 has arpeggios, 10/8 has scalar/arpeggio figures, thing is - they involve use of the wrist combined with the fingers, so they arent ideal means of determening finger dexterity, just like 25/6 - the wrist is heavily involved in the playing of 3rds.
in 10/2 the weakest fingers are forced to work more than in any other etude.
of course we can also isolate the stronger fingers, 123, but they are covered in most rapid passages in the repertoire, the purpose of 10/2 is to determine the dexterity of the weak fingers..