I'm a hard reviewer, rating wise. Last decade or so people have acted like stuff is either classic or trash, to the point that saying something is "good" or even "great" can be seen as a diss. You see this whenever the big newer rappers like Drake/Kendrick/Cole/etc drop.
My personal Nas rankings...
Illmatic 5
IWW 5
I Am 3.5
Nastradamus 2
Stillmatic 4.5
Lost Tapes 5
God's Son 4
Street's Disciple 2.5
Hip Hop Is Dead 3
Untitled 2.5
Life Is Good 4.5
Nasir 2.5
Lost Tapes 2 3
King's Disease 4
My initial rating was 4, ended up going to 4.5 over the years. I could see the same happening with King's Disease.