Excellent experience. Bertha was responsive to all our queries, and graciously accommodated a very late check-in time. The Condesa neighborhood is a very nice one to live in and to walk around (check out the bakery around the corner if you stay here).
The apartment was clean, and Bertha offered a mid-stay cleaning service as well, which was very welcome. Overall, no complaints, and I'd strongly recommend staying here to anyone who's visiting Mexico City.