I'm gathering the same thing. The sewers line and the circus line of buildings have MASSIVE bonuses to their effects (Colosseum provides +30! public order), so you have to start with a forum and build up from there. Of course, you need a ton of food to counter the usage of the big buildings, but it seems worth it. It does require a lot of care and planning, though. It seems very easy to build yourself into constant revolts through squalor (which I have not done, but someone posted about having 1-2 revolts per turn in Italy because he didn't watch his builds) or a food shortage (which I did by not paying attention. All settlements stopped growing, all armies stopped replenishing lost troops, and in the province that had the lowest net food all garrisons and armies started suffering attrition. It was not pleasant).