Well, first of all, in my subjective experiences, DTS always sounded significantly better than DD. What is the bitrate range for these two, oh was it something like 768 kps - 1.5 mps for DTS, and ~480-640 kps for DD?
Then not only is Master and Commander DTS, but it's one of the reference audio movie tracks according to those who care about these things. I've never seen the movie at home, because I'm disappointed that the video is not better.
Now, for many movies, I would also agree there is overhyping. I just don't think movie soundtracks need to be super resolving with audio. It's mostly processed stuff anyways for effects. OTOH, sometimes I swear the mix might be different, or if it isn't, then WOW. . . and I think of one in particular, oh wait I started a thread once . . . lemme fetch it:
TrueHD vs DD on the Dark Knight.