mariposa said:barrio norte is not a neighborhood, it's a real estate concept.
That may be true. I do know that whenever an Argentine moves to the area bordered by Libertador, Cordoba, and Pueyrredon, they say them moved to the "Barrio Norte".
Steve is right in that a couple of blocks either way can make a lot of difference. Streets have their "good blocks" and their "so-so blocks". Some streets even have a good side and a bad side: Santa Fe is one of them. In the most expensive section between Callao and Plaza San Martin, the side nearer Cordoba is the bad side - shop rents there are much lower than on the other side of the street.