Even the most protective Metallica fan is going to admit he's average, like. When he's good, he's very, very good. When he isn't, he's flat bloody awful. For every Blackened or Master Of Puppets, there's at least one utter clunker, or worse, utterly tired retreads of his better moments (in fairness agin, though, that's as much the whole band as him. Songs do not need sequels).
Add to that, I just don't trust peoples what don't dos rhythm guitar. There's something fundamentally wrong about that.