I can't think of a single sonic attribute that isn't better with the new O.S.  Better decay, better resolution, MUCH better bass (deeper, tighter, more impactful), superb highs with cymbals and bells that shimmer as in life and that sound truly metallic.  Voices are more human, more "fleshed-out" as it were.  Harmonic content is definitely better...The sound draws me in as never before.  I connect with the music as I do at live events.  I attend enough of those to have a good basis for that statement.  NOBODY will miss the previous O.S. after hearing this!