Cant sacrifice my growth, thereby my production and science science output for a settler and a worker. The improvements though are a Godsend, especially in epic which I play, they just cant compete to the growth bonuses. The capital always turns monstrous and the aqueducts simply rule (especially if you dont have the tech yet
)
Liberty will help you set up a bit faster but in the long run you will limp behind especially in the science race.
Given the AIs passive behavior I altered my plans to hard build my settlers now and I feel a lot more sure with tradition now.