I usually run each room as a circuit. I also run the lights on a separate circuit combining several rooms on one,to avoid as someone said to prevent being in the dark when a breaker trips because the vacuum tried to eat a throw rug. I also like the idea if I am doing service work for the customer later I know I won't have to get a crick in the neck, replacing a receptacle while holding the flashlight between my neck and shoulder. Plus the customers seem to like the idea.
