Its so fun when people matter of factly state the obvious.
The situation is what we have been discussing. At first city your getting so little science coming in that even 80-90% science wont get you writing any sooner then 48 turns. Many turns latter you can do better but I doubt better then say 35 turns all told. Seems better to go for max turn
in this situation and thats what I've observed in game as well.
The only exception might be if I wanted to be able to get code of law as well before I got philosophy so that I can get republic as a free tech. Then every turn might count if I still want to be first to philosophy.