You mean lyrically right? As far as rap-technical skills (flow, breath control, voice control, rhyme structure etc) Both Deck and Meth run circles around GZA. But they can't fuck with his lyrics..

My favourite is Ghost btw. His charisma has no parrallel in hiphop, and he's a solid MC in terms of lyrics and technical skills as well. Definitely the most well-rounded MC in the clan, and the one with the best discography.