Ligeti etudes... there is a great one that descends chromatically...not sure which one it is.
I'm not necessarily looking for pieces that break new ground, I was thinking more in terms of etudes that both develop technique and would be good to use in competitions. It sounds like these etudes might meet those requirements. I suppose, then, that you would recommend I purchase book one of the etudes instead of book two? I can try book one out first.