That depends on what you are cooking I think. Most things I am normally inclined to cook require me to attend to them while they are cooking. Slow-cookers eliminate that and do other things instead, like go to work.
Even if you are cooking something relatively hands off in your oven.. how often do you leave your home while your oven is on? You are locked down to that location for the duration of the cooking time.
Even if you are cooking something relatively hands off in your oven.. how often do you leave your home while your oven is on? You are locked down to that location for the duration of the cooking time.