Lester has participated in 2 games. By tomorrow, Ortiz will have participated in all 6 games. If that argument doesn't hold enough water....
Decades from now, when people speak of "famous red sox players", David Ortiz' name will be mentioned along with the likes of Clemens, Williams, Yazstremski, Ruth; Lester will be long forgotten. The same can be said of each of their performances in this series alone; Ortiz' is already stuff of legend, while Lester is just another one of many who have two rock-solid WS pitching performances under their belt.