We didn't actually meet Gisela however she did respond quickly to email and texts. Her friend Juan met us both coming and going and was very obliging when our plane was about 3 hours late. I can't say enough about Juan - he was so helpful and has a great sense of humour.
The apartment was perfect for our needs although small by North American standards. We felt safe and comfortable in both the apartment and the surrounding neighborhood and the location was convenient for both walking and transit use.
Everything was exactly as advertised and Marta and I enjoyed our stay there thoroughly.