I'd vote for the Carrefour. La Cantine is too expensive for my tastes. Also, like Nicholas I appreciate anything being close to Gare du Nord.Leon
To be fair, both places are 5 metro stops away from Gare du Nord (with one change each). Walking distance is 1.6km for Gare du Nord-La Cantine and 3.2km for Gare du Nord-Carrefour Numérique.
Vincent.
