The main issue with the soundtrack is that it sounds more like a Greatest Hits compilation. I cannot recall, off the top of my head, any really great original songs. Most of the standouts are remixes of older tracks. To the point above, though, my opinion may change when I listen on headphones.
All of the Disney world tracks were amazing to me. I remember like 2 or 3 other unique boss themes I enjoyed but I haven't looked up their names yet or anything. Otherwise yes, the remixes were really the stand outs this game. I feel like that was partially to invoke nostalgia since its the end of the saga though.