Which do you prefer, a stroller or a carrier?

If my baby can sleep in a stroller without any fuss definitely a stroller so that I won't have a backache of carrying my gal around and trying to eat over her head. But truth is most babies can't sleep on their own in the stroller when they are young. That's when the carrier is most useful. If I go out with my family or husband I will bring both out. Carrier is used only when I want to force my baby to nap. But if I travel alone I will only bring carrier as it will be too much for me to handle a stroller on my own.