Carla's place was very nice. The apartment is clean and spacious (comfortably fits 2 to 3 people), and a few minutes away from the metro and the national archaeological museum. It is also one stop away from the main train station as well as the downtown area with many tourist attractions. I also walked there, and it took me about 20-30 minutes.
Communication with Carla and her associates was impeccable, and they were accommodating at check-in even when the train delays caused me to miss our check-in appointment.
I did face a little issue with internet. For some reason, there was no cell network (TIM) inside the apartment, and while I could connect my phone, I couldn't get the Wifi to work on my computer. But in general, it wasn't a major issue.
I would definitely stay again at this place.