I would definitely recommend staying at this apartment. It's very good value for such a great area.
I'm pleased to say that Rebeca is an excellent host - she was really attentive and answered our questions quickly (via Whatsapp). She cared about us having a good stay.
The flat itself is great for a couple. The living area is a good size, the shower is pretty slick and actually the bed was particularly comfortable. We didn't use the kitchen but it's spacious. The flat is on the ground floor which generally isn't a problem but you can hear some noise from people coming and going from the building. This isn't a significant issue and there isn't much noise from the street. Above all, Condessa is a cool area to be in - we found loads of cool bars nearby: try the Mezcal bar a few doors down and the coffee shops/ cafes halfway down Av Tamaulipas, there's a big cluster of them, kind of off to the left when you cross at the big crossroads. Well pleased to have stayed there and not Centro Historico.
We had a great stay and Rebeca is an awesome Airbnb host. Thanks Rebeca!