Think I'm straddling a line here with the sex experiment. Don't think couples should 'schedule' sex on a daily basis because if one or both of the partners aren't in the mood -- then sex just becomes another obligation which is a complete romance killer.
However, I think couples should 'make time' for sex by prioritizing. For example, you can skip watching your favorite show after the kids are in bed to spend time with your partner. I think there are choices we can make in our daily lives to leave time for our partners without making sex feel scheduled ... says the woman with no children .... How do you make time for your partner?