On addition, i really love SE4. It is my favourite game, and i have a lot of games. I just think that the AI is pretty dull, stupid, cheats and doesnt mean a challenge at all. I love SE4, but only when modding or playing against humans.
On SE4, you decide if the AI cheats. Its the computer bonus setting... Lots of people say that the TDM floral empire AI is very good, maybe you should try that?