According to google, the phrase "Mi casa es su casa" dates back to the Spanish conquest. I would have sworn Gabriela and Carlos invented it! When I arrived at the door, I was greeted with a warm smile and a friendly invocation to come in. "This is your house" he said.
Once I entered, I found a home decorated with stylish touches and a cultured appreciation for the arts. (Ask Carlos about his art collection). The bedroom was spotless and wholesome; there was a kettle, with bottles of water and coffee/tea ready. Extra blankets, clean, puffy soft towels, you name it. It felt cozy.
The walls are reinforced with concrete, so it's quiet enough in the room. And the location is in a safe, trendy area of Mexico City, with a lovely park nearby.
Overall, for the location, hospitality, and coziness, you can't go wrong staying with Gabriela and Carlos. I would stay again in a heartbeat.