I recommend Martha's apartment to everyone.
Not only it is well located near subways and buses, it also has a vast daily trade for the tourist: grocery stores, restaurants, coffee shops, laundry and even hairdresser.
The apartment is not big, but Martha did everything to make me feel at home. I was able to use the well appointed kitchen and bathroom. The bedroom is the ideal size for the kind of travel I usually do: cultural tourism and studies. During the winter it was great to have a heater that even though it made some noise, it never bothered me (otherwise it could be turned off). The window of the room is close to the building's exit, but at night I had no problems. Martha really surprised me, because we could also have the kind of conversation that I love, she introduced her culture, and pointed things around town.
Thanks for the great reception o/ :D