So I played a semi ICS game, at King level (need to try next level), a lot of my cities were 3 and 4 tiles apart, but I still had a good amount of cities. After I got my happiness squared away, I annexed way to many enemy cities, and by the time I looked, I was at -80
, I was in the middle of the Renaissance age, about 2 techs from going to industrial age. Only one civ had gotten to the industrial age so far, and was like a turn or 2 prior to that. I ended up building a library in every city. And then worked on upgrading culture and gold, and a little bit more happiness so I could sprawl more.
I ended up beating the competition to modern age by a good 20 turns, and I still only had like, ignoring my initial cities, having only a library for research. Because science doesn't get modified like culture, due to the number of cities, I was able to stay significantly ahead of the computer in tech level the rest of the game. I probably would have won a science victory, except I had already turned off that for a victory condition. With the fewer buildings in my cities taking away my profit, my income on regular turns was like +150, and during my GP GA, I was making something close to +900 gpt.
So, after all this rambling, if you do an ICS game, and do it properly, at most only build a library in MOST cities. Focus on Gold and Culture, and if you need to, or want to, some happiness.

I ended up beating the competition to modern age by a good 20 turns, and I still only had like, ignoring my initial cities, having only a library for research. Because science doesn't get modified like culture, due to the number of cities, I was able to stay significantly ahead of the computer in tech level the rest of the game. I probably would have won a science victory, except I had already turned off that for a victory condition. With the fewer buildings in my cities taking away my profit, my income on regular turns was like +150, and during my GP GA, I was making something close to +900 gpt.
So, after all this rambling, if you do an ICS game, and do it properly, at most only build a library in MOST cities. Focus on Gold and Culture, and if you need to, or want to, some happiness.