The etude is chopin's 10/8, why not? My teacher thinks it makes sense, and I think it will make sense too, if I can play it. Nightmare scenario - weak, uneven arpeggios, uneven with uncontrolled accent marks where the thumb lands, tendonitis from bad practicing, etc. If anyone asks, THIS is why I so very much prefer practicing things like this SLOWLY. I mean there is nothing to fear at half note = 80, and it will eventually get very fast and clean... right?