City states are too powerful in their current state.
First of all they are far better to ally than to fight against. Its just not worth fighting with them.
Second of all they are too easy to ally and the AI doesnt seem to focus on befriending them much.
Third of all the bonuses they give is insane, more food for all your cities and more SP points.(and units allthough i havent found that too useful yet)
In the game im playing a huge amount of my excess food comes from city states, aswell as the majority of my SP points.
With that said i absolutelly love the introduction of city states, they just need to be tweaked abit.
