Generally, a lot of people prefer the "Old Em" (1998-2003) over the "New Em" (2008-2013). Why? Perhaps he was newer, more innovative, less of an insider. But there's more than that.
My theory: New Em is no worse than Old Em (and in many ways shows evolution), but Old Em is MORE COHESIVE.
Music is an industry where cohesion matters above all. The Beatles, individually, are unremarkable, but the way they assemble every single aspect of their music is quite remarkable.
New Em has displayed he is just as capable, if not better, in every single aspect: lyricism, wit, delivery, flow, hooks, etc. But it feels like each song sacrifices something, whereas most of the songs on the Eminem Show had all of those things without sacrificing any of them.
Berzerk and Rap God is a prime example of this. Berzerk had an amazing chorus and functional verses, whereas Rap God had skillful verses with a forgettable chorus.
Or do we look at Relapse and Recovery? Relapse had the lyricism with no real message and Recovery's songs had more message to them but sometimes suffered lyrically.