We've always been on the same floor. Essential when they are babies, darned convenient and safe when they are toddlers (and overnight potty training), and terrific when they are teens and you can see how late they stay up doing that paper due first period. Or the faint blue glow under the door when lights are out but an electronic device is still going.

When I was 13 my family moved to a house with the master down and kids up. I really didn't like it because I felt isolated from my parents, and they were totally unaware of what my brothers were up to in their bedrooms.