Based on what I listened to, I preferred the work of Debussy over the work of Mahler. There are at least three reasons for my preference of Debussy's work.
While I appreciated Mahler's classicism, his diversity of tempo and mixed rhythms, I had some difficulty accessing and relating to Mahler's work. As a progenitor of modernism, I related more to Debussy's work. I especially liked Debussy's similarity of musical form with more modern music. For example, the intro to L'après-midi d'un faune (Stokowski) part 1/2, with its opening flute solo, was similar ...