sniggl wrote:...the solemn charakter of this Allegro is very important. And you can not play it "solemn" if you play it too fast.
My two cents.
Actually, according to my dictionary, "solemne" not only means "solemn" but it means "completely" or "utterly" as, e.g., you would say "he is utterly (completely) reliable." In this regard, "Allegro solemne" could be interpreted as "allegro molto" or "allegro assai." That would seem to emphasize a more hurried and less lyrical interpretation. A "solemn" allegro comes close to being an oxymoron when you focus on the root meaning of "allegro", viz., happy or cheerful.
But my preference for the faster, more hurried style stems from providing more contrast to the contemplative, and slower, first two movements. I think, when treating all three movements together as a single piece, a faster third movement, with more bite, provides the more complete experience. Who knew that Barrios could be a controversial as...health care!