Mine has to have 14 full length dividers and set up where my clubs are in the order I like (little OCD), separate putter holder, umbrella holder, enough room to fit in raingear and a long sleeve (the weather in cincy is unpredictable), and a cooler.
Style and color are big factors as well I don't like anything to plain or ordinary.
Just bought the new Titleist lightweight cart bag for christmas.