Thanks! I agree about that. Schubert isn't Beethoven. There is less internal drama and more on the surface drama (in general). No criticism. They are just so different and I don't see why they are compared so often outside of some figuration and harmonic similarities. In any case, thanks for the watch!
I agree that Schubert isn't Beethoven. One difference, I think, is that Beethoven was much more optimistic than Schubert, lots of struggle and angst in Beethoven, but it usually resolves into something positive. Schubert, on the other hand, is pretty dark, even in a major mode, which is not surprising given that he knew he was dying young.
So in this Impromptu I hear, at first, a pretty cheerful, spring/summer scene, flowing triplets like a brook, sunny mood, then when you get to that circle of fifths progression starting in Ab minor, you get some nostalgia, maybe anticipatory nostalgia for what is sure to be lost. Then in the B section you get an image of death, a bleak winter landscape, cold winds, etc. But at that point it's just a thought intruding on the otherwise pleasant scene, which comes back and gets repeated. But then the coda accelerates, the wintry bits return, and even the flowing triplets get drawn into Eb minor. Winter/death comes sooner than expected and it's all over. Pretty bleak, I think. It's not that the opening, sunny, flowing bit isn't lovely and beautiful, but there's something ominous there almost from the start, and it becomes more intrusive throughout the piece.