Ricardo's place has excellent location, walking distance from many sites in the historic center. He is also helpful recommending the best ways to reach outer sites and provides a transit card.
He is very responsive - we had no problem with check in or any part during the stay. Moreover, we were in Mexico City during a water shutoff. Ricardo went the extra mile helping prepare for the shut off and store water. He did such a good job that it was a non-issue. We highly recommend staying at his place.