Oh, and I ALWAYS use GE's to rush Wonders; nothing sucks like losing a good one needlessly.
I agree that generally GE's are best off used to rush Wonders. However, I have found that I might do things differently if some of the following factors are present:
- It's an easier difficulty level
- I'm in the tech lead
- I've scoped out the map and can see that none of the other AI's are building wonders
- The other AI's have low "Wonder" flavors for their personality
In these cases I can usually just hard build all the wonders anyway, so I'd rather save the GE's for something else.
Of course there's also the situation where I'm playing Domination and/or warmongering and would actually *prefer* that the AI's build the wonders since it saves me the trouble (though several of the wonders have a "free" effect that is only granted to the builder).
Manufactories can be especially useful if:
- You're finishing Freedom (doubles production output of the improvement)
- You're playing as Korea (you get the extra Science)
- You want instant access to a Strategic resource you just discovered
- You want to quickly finish a key Project (especially Apollo or Utopia), since you can't hurry projects but the extra hammers might shave off a few turns
Normally, I tend to get one or more GE's in the late Classical or early Medieval Era (either from the Liberty finisher or developed normally if I managed to build Artemis/Stonehenge/Pyramids early).
In competitive games, I may use the GE to rush:
- Hagia Sophia (though I rarely find the AI bothering with HS so I usually don't need to rush it. Obviously, I choose a GE for my free Great Person and usually hurry PT, though occasionally there are games where I build the PT normally and save the GE).
- Hanging Gardens (since Mathematics is out-of-the-way in terms of tech path, I often end up rushing this)
- Chichen Itza (AI's seem to prioritize Civil Service and Itza seems to be the AI's favorite Medieval wonder).
Normally I don't bother rushing Renaissance or Industrial wonders, but I will often save several GE's for the end game. Especially the U.N. (for Diplomatic games) or Sydney (for Cultural).