I don't think Shakespeare, Dante, George Lucas - anyone - could have written Jadzia Dax in a way that Terry Farrell could have played effectively.
It's subjective, of course, but from my point of view the writers definitely improved how they wrote the character and Farrell's acting/comfort with the role improved quite dramatically over the course of the series.
suum cuique pulchrum est
(^ I'm gonna need a speaking coach for that one.
