If you happen to listen to the first 5 Pearl Jam albums, it's obvious how Vitalogy was an attempt to make music a bit more complex; it didn't please everyone. No Code represents a more timid attempt, and even there, the sales response was good, but you know... and poof, then everything falls into the Arena Rock or Room Ballad pattern.

I already knew this, but hearing it all in a row really hits you in the face. And Vitalogy, quietly, is still awesome. The others are "great rock albums," but they don't have anything particularly special; they're like "Vasco Rossi if he were good and skilled" (a huge example just to get the point across).