Free roaming works for some, I keep mine caged when I am not at home or am sleeping. The reasons why I prefer this option is because coming into/ out of my apartment I do not want to have to worry about them slipping out, they get into EVERYTHING (who ever coined the phrase curiosity killed the cat never meet a ferret), they will eat anything ie shampoo, conditioner, or get into your pantry for cookies or crackers. Plus if I'm not reminding them with my mother glare to use the litter box, the closest corner is where they will go. In honesty I can not understand how it does work for some people.
