This is by far one of the most touching and beautiful pieces of music I've listened to. The consistent, quiet background parts aren't overpowering the melody, and the harmony of the main part with the background is wonderfully done. There's just enough variety to keep one interested, and everything is so well planned out. A plethora of instrument types work very well here, too. And that single sickening chord toward the end is enough to keep anyone awake for a good hour at a time. Orchestral music with this many parts isn't by any means easy to work with, but this is dead-on to my ears.
Personally, I think you nailed this one. Amazing job.