The recent submission by Marcelo made me dust off an old curious CD of an Italian pianist, Massimiliano Genot, playing those forty etudes (plus Liszt's opus 6). I find Genot's liner notes very interesting. Follow some of his thoughts.

Here Czerny demands an extremely fast execution, a largely ignored element until the present day. I am convinced, however, that by following the composer's own instructions on timing, we not only satisfy the didactic aims of this collection, but also, with pleasant surprise, reveal an aesthetic sense, often comic, sometimes dramatic, which has been lost in the traditional manner of performance. Furthermore, increased speed brings about a change in the physiological perception of sounds. They are no longer perceived individually but as continuous resonant trails, an impressionistic conception of sound similar to that Czerny's most illustrious pupil, Franz Liszt. The main obstacle to achieving the original metronomic timing on a modern piano is due to the larger dimension of the keyboard action and, consequently, increased inertia. This has made an in-depth study of technique necessary, especially concerning the use of arm-weight and double repetition mechanism. Technique of weight transfer touch and hand rotation touch in particular have helped to reintroduce much of the original fingering.

For the insatiable piano lovers among you , I've uploaded here a sample of these studies (Nos. 6-12-15-17-22-29-39).

They're still wretched.

You're not insatiable, leave them alone!

My god, the speed on the second etude is simply insane!! I wish I could match that speed...
Thanks for uploading the file.