We had a short stay in Alejandro's place during our first night in Mexico City. The location was really convenient and felt really safe being located in a more upscale neighborhood. The place was small, yet pretty modern and clean. Alejandro was very responsive and made sure we were safe upon checking in. Since we were there during the holidays, the neighbors were up partying pretty late and could be heard pretty easily, but I'm sure that is not a common occurrence throughout.
If you are looking for a comfortable and convenient place, then I recommend Alejandro's place.