Wow, Fernanda's place really is excellent. It's very spacious and well-decorated and Fernanda is a great host. She's very easy to communicate with and went out of her way to greet us in person when we arrived. Check-in was also easy with the doorman and lock box, but the fact that she came by to say hello and welcome us to the apartment made us feel well taken-care of! On top of that, absolutely everyone in the building -- the doormen, the neighbors, even the lady who comes to clean when you check out -- is incredibly friendly and helpful.
The apartment is in a really great neighborhood with tons of restaurants and shops and very close to the metro (Fernanda supplied us with a very detailed guidebook that helped us to locate the best spots). We felt safe and comfortable the entire time, even late at night, and really enjoyed walking around Condesa and the surrounding areas.
I highly recommend you stay with Fernanda!