In my opinion, these are DTs best sounding albums, and I find much of my enjoyment of any album is determined by similar qualities that I don't have the knowledge to describe. Words like "clear" and "spacious" come to mind. I'm sure much has to do with the band's obsessive precision, which is apparent even on terrible bootleg recordings.
I'm hoping for this to be a discussion of what recording techniques, instrument effects choices, etc result in the overall sound qualities of these records.