We had a great stay at Carmen's place, it felt very cozy and she had documents all ready for us with her suggestions of things to do and places to eat which was really useful. Good thing she was honest about the neighborhood because it truly is sketchy, however the building is really safe with a gate to get in. A homeless person talked to us once but otherwise we did not have any problems, they mostly ignore you. I really suggest taking the bus to go downtown though, it is only 3-4 stops away (the 004&007 pass all time).
We did not meet Carmen as she was away during our stay, but she was very quick at responding beforehand and you can tell she cares for you to have a good stay.