Why does eminem use dopey voices in his new album?

Em was my idol for years after I first started listening to him. So I was really excited about his new album, rellapse coming out. I've been listening to his songs today and I love the song "beautiful" but some tracks are spoilt by his experimentation with his voice. That should be done in the studio, not on a released album. What I mean is that his lyrics are better than EVER before, and will forever be unmatched by his rivals, but songs that would be otherwise superb such as underground and 3AM are ruined by the weird voices he sings in. Anyone else feel the same way? I will be buying the album though, overall it kicks ***.