As a digital nomad and someone that rents airbnb's for long period of time my review will be long.
Overall, Cristina's and Berny's place is probably the best place possible you can stay in Mexico City. I was here for a month with a friend wifi, water temp, water pressure, home supplies, cleaning, comfy bed and pillows and the rooftop were all great.
If you plan on having a roommate layout do note that one room is significantly larger than the other. The unit is on the third floor of the building facing the street--if you are sensitive to noise you will hear cars and people at night and in the morning (but not too noise for Mexico City standards). Both bathrooms are on the first floor and the second one is fairly small, but manageable.
The internet was great. My friend and I both worked all day and had no issue video conferencing at the same time.
The apartment is filled with everything you can possibly need from the kitchen, robes, extra blankets, umbrellas, and washer and dryer which was very convenient. Cristina and Berny have done a great job at anticipating what may be needed.
We did use the cleaning services offered. Because of all the dust in Mexico City the apartment does get dirty fairly fast. The cleaning lady came once per week and did a good job at leaving the place spotless. She's very nice, respectful, and doesn't touch any personal items.
Communication with our hosts was great--they were there for anything we needed and very kind.
Again, highly recommend this spot and cannot beat the location. There are so many great restaurants and parks around.