I know the last two posters said turn it to LPCM, WOW is all I can say.
I did not think that I would be able to tell the difference at all or it would be minor, I was wrong. I was watching (and do not make fun) Enchanted and I watched the scene in the park where they sing the song with the steel drums.
Now with this movie you can change the audio setting quickly like one second... well I kept playing with it during that scene... and WOW.
When I turned it on the Dolby TrueHD soundtrack, it was so well defined, the base boomed with tight accuracy, and the sound from the speakers appeared louder (or more clear). In Dolby track, the base did not boom as much and the bass seemed shorter and kinda muddy... quick rathering than holding the sound, I hope you understand. Overall in Dolby the speakers seemed to get quiter (or not at clear).
If you get a chance, just change the soundtracks and watch the same scene over and over in Dolby versus Dolby TrueHD soundtracks, there is a difference, WOW!