Great read. Jumping ahead a little: The Sim City 4 community is one of the better ones I've ever seen. 13 years after the release, and people are still releasing high quality mods and custom buildings. The community has kept the game alive for all these years, and made the SC4 experience many times better.
How do you feel about the new games like Cities Skylines? How would you rate it against SC4?
CS in itself is a better game, but the SC4 custom content scene is still superior making it a better city designing experience (only simulation worth caring about in SC4 is modded traffic imho...).
CS is very moddable, has an active community releasing custom content using the steam workshop, making it very accessible. Oh, the time I've spent trying to browse early-internet-looking japanese websites to download awesome custom buildings and their dependencies.
But just give it some time and we'll have at least as awesome custom content for CS as for SC4. As I see it, Colossal Order are the new masters of city building games.