We stayed with Host Me Tender this past November. The place was exactly as advertised and we really had an excellent stay. It was extremely clean and the location in Condesa is phenomenal. Walking distance to a lot of cafes and bars, and centrally located enough to explore all the different areas of MXC (i.e. Roma Norte, Juarez, Historico, Polanco, etc). Alex and Javier were also very hospitable, helping with restaurant tips and guides on neighborhoods. The only slight disadvantage of the apartment I would say is that it got really cold at night and the full-size bed is extremely firm. However, a space heater was provided and obviously mattress pressure is a personal preference.
Overall, our stay was terrific and the apartment provided a perfect home base for exploring MXC.