Looking at recent comments on the Steve Hoffman site, and they’re really ripping on this. Personally, I think the 5:1 mix sounds great. I listened to half the Montreal concert and the band was killing it. On the Hoffman site they are mulling over the numbers.
I get a bit of tinnitus so find some records difficult to listen to. I think it tends to be heavily compressed albums, as you'd expect. I listened to this fine last night, so it never occurred to me that it was overly compressed.
I see there are also complaints about differences in the mixes. I have sympathy with someone who knows and loves an original mix so well, but again, it sounded great to me. And interestingly, I see from the main documentary that the band were not happy with the original mix even at the time. (They didn't all participate in the mixes and wanted to remix but EMI said, no, this will have to do.) So it's possible that there are changes that have been made on purpose. (Though I would have expected the Steven Wilson approach of including the original mix as well if they had knowingly changed it.)