Bravo, barnardo! Kapustin's music is reputed to be very difficult to play, so many if not most classically trained pianists (including myself) don't even attempt it. You had great courage to do so. (Incidently, Kapustin denies that he composes jazz per se, as he has never considered himself to be a true jazz pianist. Interesting.) Regardless, I believe that your recording is superb. I don't know enough about jazz idiom to critique it in detail. But the energy, excitement and beauty of your rendition is most convincing indeed and speaks for itself. You put it across to the listener very effectively. Congrats!
David