GZA has Nas in the wordplay and punchline department. In terms of experimenting with different flows, internal rhyme schemes, and multisyllable rhyming, I give the edge to Nas. Storytelling and depth of content I also give to Nas. In terms of song concepts and use of metaphors, it's very close. You could make a strong case either way. Vocal tone and whose flow you prefer is more subjective, but to me it's about even. Overall, I think Nas is the superior MC.