Here’s a brief review of The Anthology of Rap in New York Magazine, in which the reviewer claims Big Daddy Kane as the greatest rap lyricist of all time. I like that he differentiates between lyricists and performers, because great writers are not necessarily great performers and vice versa (though Big Daddy Kane was certainly superb on both counts).
If this short review is representative of the book, the book could go a long way toward debunking the common complaint that all rap is the same, or that it’s all about a very limited set of subjects (which is something any fan already knows).
Personally, though, I think Rakim was superior to Big Daddy Kane.