Hi Emill,
Ah, the impreciseness of tempo verbiage and indicators. Here in the "Winter Wind" etude we have, after the introduction, "Allegro con brio"--a rapid vivacious playing with vigor, animation and spirit. In the Paderewski Edition there is a metronome marking of a half-note = 69. But the Arthur Friedheim edition for Schirmer shows a half-note = 58. There are probably other variations in other editions. Either of these markings though is definitely in the highest reaches of allegro, that is, almost touching vivace. Chopin's intent was to produce a whirlwind of sound and at these tempi it can be realized.
Enzo's slower rendition is a more cautious and careful one and allows time for more control. I believe that the faster rendition is probably closer to Chopin's actual intent. It has a lot of brilliance, thus is more exciting and satisfying in my opinion. I would never let go of slow practice as the foundation to ensure articulation and accuracy. Following that discipline, I would change from practice to performance at a fully manageable tempo. Then I would keep incrementing the speed at only two notches on the metronome each time. As speed increases I would be listening for accuracy and clarity. As soon as errors or note omissions appear, I would go no higher until I could remedy the loss of control. Only then would I try to edge it even higher.
I have to admit that I'm an old school pianist not willing to sacrifice risk taking and individuality for pure precision. Today it seems that there is too much of a fixation on absolute precision. Audiences want the artist to communicate the mood, emotion and meaning of the music to them. If the artist makes that connection, then a finger slip and a few dropped notes aren't going to matter in the larger scheme of things. Just my opinion.
David