well... if your simply a writer, than you have more chance of being better lyrically than a vocal MC... but no matter how amazing your lyrics are, it wont mean shit if you flow like a ape... Eminem is prolly a better writer than most people on this site... but you'd have to hear infinite to know that... unfortunately he dumbed down after his underground days, but hes still better than most people... it all depends... the most amazing writer of all time was prolly someone like Shakespeare or something, but he wasnt vocal, yet he would get props for wordplay if he just updated his english a bit... but tell him to rap... the first response youd get after "whats rap?" would be "i cant"

and then you got 50 cent who can flow with monosyllable rhymes but is a hopeless lyricist