nah, I've watched them as remux on my PC (and receiver) and I've converted both tracks to .flac with eac3to which means dialnorm and DRC both got removed. and I've limited the 7.1 output to 5.1, because I don't have 7.1. theoretically, the 7.1 track could sound as good or maybe better on a 7.1 system, dunno. but on a 5.1 system, it did not.
(to anticipate the question: I guess the remaining 2 channels didn't get dropped, I used the madflac filter and to me it sounds unlikely that madshi would allow lossless sound not being put out as lossless by dropping audio information. So I guess the sound of those 2 additional channel has been put out via those 5.1 channels, but you'd have to ask madshi in order to clear this up).