I'm playing samples of this "Tusk" DVD in 5.1 right after playing samples of my "Rumours" SACD, and you know how much difference I hear between the two in perceived loudness? None. (And I didn't adjust my volume knob one iota between the two discs.)
I think Jon's frustration with the loudness factor on this disc was particularly exacerbated by the fact that he played it right after playing "Idlewild South", a fully lossless 5.1 surround disc with great mastering, one that doesn't fall for the old syndrome of making it loud just cause it can be.
If this 5.1 surround mix had been released on DVDA as originally planned back in the day with the same mastering we are hearing now, none of us would have batted an eye because we were used to a more compressed sound then. Since that time we have been treated to more dynamics-friendly mixes, especially from Steven Wilson, so hearing an artifact of times gone by is more painful nowadays than it would have been ten or more years ago.
None of this excuses the loudness factor of this disc, but I hope this can bring a little more perspective into what we hearing and how what we hear before or after immediately affects our consciousness. I'm still more pissed off at the lossy factor of this disc, but hey, we all fight certain battles for certain reasons, so as long as it's a noble battle, I say "Fight on, Quad people!"