Formulas are more expensive. Formula-feeding doesn't smell as good. Different intestinal bacteria go along with formula feeding. The different bacteria, along with less effective digestion, mean smellier diapers. Even their skin and breath smell different.
Breastfed babies are more portable.
A nursing mother never lacks for the right food at the right temperature in the right amount at the right time - anywhere. Without bottles and pacifiers, nursing babies are simpler to carry along. Breastfed babies are healthier. Formula gives no protection against illness, so formula-fed babies are more prone to diarrhea, ear and respiratory infections, skin problems, and pneumonia. Formula-fed babies tend to get sick more often and recover more slowly than normal.