major lack of realism when discovering techs!

[rysmiel]

How would this affect the game, though?- That's the main goal I am looking for. For one, tech in ancient times would be both more even and more guarded between players. If any civ has a massive lead in commerce, some of this will diffuse into world tech for other civs. Playing an isolated start has even more of an effect, because no contact with anyone else means world tech has no effect on you.

It's an interesting notion, but I'm really not seeing what the advantage is; tech diffusion from the leader strikes me as a serious disadvantage whether you're the leader yourself or not, and I am not sure I see the more useful monopolies as gain enough to compensate.