Federico's place was great.
Federico arranged for someone to be at the apartment early for us, and allowed us to check in early which was a huge help.
We had a group of 6 and had no issues with space. It was very comfortable.
The location is great, very central, and with uber there were no issues getting around the city. We had no worries about safety at any time during our trip, including late at night in the area.
Some light sleepers did have issues with noise since it is on a larger street, but I had no issues sleeping personally.
We also had some issues with not having hot water during certain times of the day (i.e. early morning) -- not sure if this is an ongoing issue, but we were able to work around it and it wasn't too much of an inconvenience for us.
The elevator for the unit is quite small, so it's a bit of an inconvenience for larger groups, but again, it was a relatively small issue.
Overall, I would recommend Federico's place, and would highly recommend Condesa as an area to stay in.
As a bonus, Postales de Cafe around the corner is a great coffee shop with some pretty good baked goods, and we had a good (but slow) breakfast at El Rincon Gourmet half a block away.. and there are a ton of fantastic taco joints in and around Condesa.