IMO: The reason you find most recipes call for "30 minutes" is due to our 'I want it NOW' culture. People are not willing to wait four to five hours to eat. Italian grandmothers across the nation are turning in their graves, knowing that the family recipe has become a McDonald's recipe.
I highly recommend you slow cook your chili and your spaghetti sauces. By cooking slowly and for a length of time, you will experience flavors you did not think were possible.
This is why Wendy's Chili tastes rather good for fast food...they made it fresh in the morning, and it has been sitting in the pot for hours before you bought it to dip fries in.
An old roommate used to make chili. We'd get a bowl the first day, with lots of "water". We'd make peanut butter sandwiches and soak up the "juice" of the chili, then enjoy the meat and such in the bowl. Then we'd add as much water as we took out to eat, and put the whole thing in the fridge. We would repeat this ritual nightly until the whole thing was gone. Each night, sitting in the fridge, the whole creation got thicker until by day five it was a delicious spicy mush.