Lu's place is excellent for a large group of 5 people. It is clean and has hot water, excellent wifi and comfortable beds.
The area is not as safe as other areas, such as Condesa or Polanco, but the advantage is that is very close to the historic center, and within walking distance to sights.
Lu answered all of my questions and was waiting for us at the apartment. She also let us stay a couple of hours extra, because our flight was later in the day.