Slayer has been big on the superclipping for awhile now it seems. It makes it hard to listen to for long periods of time, but I sorta figured that was done on purpose. It does provide a decent effect I suppose, although I'm not sure I really like it other than on Divine Intervention because it isn't too harsh.
yeah divine intervention doesn't actually clip... maybe at a few places, but it's not what i'd call terribly mastered by any means. i don't know how the following two albums sounded because slayer broke up after divine intervention.