well - there is also:

a) cooking in someone elses kitchen (though you would get familiar with it if you did it on a regular basis)

b) cooking with someone elses recipes (though the show I watched said they helped people with that - adding or deleting or changing quantities of spices etc)

c) needing freezer space - since you are cooking up to 12 entrees at a whack (not 12 servings of entree - 12 entrees)