We had a wonderful stay in Francisco's modern flat in Colonia Juarez. The building has a 24-hr doorman who let us in, and keyless entry to the flat, which was very helpful with our group. It was quite cold when we got there, but Francisco came over right away with some space heaters (central heating is not generally available in Mexican apartments).
The beds were very comfortable and the place was spotless. The roof deck was a little chilly in January, but nevertheless welcome. The kitchen was functional, and the living room was a pleasant place for the family to gather. There was lots of closet space, and a good washing machine.
We love the neighborhood, which is near where our daughter lives. It's quiet (except for street construction, which is no one's fault!) and untouristy but very close to the Paseo de la Reforma and the more chi-chi neighborhoods of Roma and La Condesa. It's a bit of a walk to the subway, but taxis were easily gotten on the nearby Calle Atenas.