I still thought the BD sound was better than what I heard in theaters. The theater sound didn’t have enough bass, punch, or impact. The star wars theme in the opening crawl didn’t have near the impact I remember it having when I saw ROTS in the same theater. Although it is possible the speakers haven’t been maintained well.
Well, I for one thought the theme sounded kinda weak both in the theater, on the soundtrack CD and on the BD. I think it’s just a matter of the performance itself lacking intensity.
Though I agree with your point about dialogue volume. I tend to find in live action movies (animated films rarely have this issue) that I have to put the subtitles for the hard of hearing on, simply because the dialogue is often drowned out by the sound-effects. And for what it’s worth, I did not have this problem in TFA.
Part of the reason for the perceived lack of intensity is because John Williams did not conduct the opening theme for TFA. They instead brought in a guest conductor, Gustavo Dudamel, who is the conductor for the Los Angeles Philharmonic.