@Thadian:The game suffers from a very difficult balance in the late game, where there are so many possible things to build, and they all come at the same time. It is normal that they drift so much in usefulness. At release, factories were the only way to build something in a city, and you had to rushbuild them, because they were so expensive. They have now nerfed it, while reducing (a lot, apparently) the costs of later buildings. Basically factories are the new late game workshops, which is completely cool: needed but not compulsory.
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They have also reduced the proportional cultural bonuses, which were completely aberrant before: you could more or less forget about SPs till you got free speech, radio towers, Cristo Redentor, etc (-50% policy cost adquisition and x3 culture!).
The only nerfs I don't like (yet?) are Pyramids and Sixtine Chapel, but in the later case, considering how they have taken out nearly all proportional cultural bonuses, and added more base culture, I guess it was needed. We'll still have to see how the other one works.
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And again, I love the SP work: extra much needed culture in honor, internal rebalance of Piety, later free GP from liberty, complete rethinking of Freedom, the later three SPs being mutually exclusive for extra late choices... and then the cherry on top: bonuses for completing full branches!
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We will have to see how much more difficult it is to get to Globalization now. If it is difficult enough, I may even enable diplo victories again!
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And one of the most waited fixes: RA!
Civ 5 won't play the same at all anymore. And we will have to rethink how to work on the early happiness issues much more, unless the first SPs come so early that we can get to the new/improved happiness sources. Maybe we will start trading lux resources for lux resources with the AI, now!