Actually Id like higher levels with AI bonuses, but minus the human player handicaps on top that Civ IV has. Why do I also have to pay so much more maintenance and have a useless economy while the AI is getting a 80-90% bonus?
If the human player didn't have to pay more in maintenance, higher research cost and so on the game would be way too short. Also, to keep the AI relevant they would need even higher bonuses. That would lead to an absurd tech-pace.
Out-teching deity-AI with no tech trading is certainly possible, but its not always what you want. No tech trading slows down the AI too.