Federer does shank balls. He shanks them because he takes so many ball early and on the rise. Plus the amount of spin that he and the other players put on the ball today makes it really difficult. It does not have to do with his racket. I bet if he stood as far back as Rafa he would not shank as many balls. Of course then he would play as well either. It is not his game style.
Wilson 6.1 95s