I spent about a month and a half at Susana´s flat and I can't feel more pleased for the experience.
First of all, it was very clean and even better than the pictures they display.
It has a fantastic location since its near the beach, a metro station and one of Barcelona's most important Ramblas, Rambla del Poblenou were you can find variety of restaurants.
Now, regarding to the family; Susana, Gustavo and Ana are a wonderfull family and they did everything they could to make me feell as if it was my own house; they were always willing to help me and even took me to the doctor when I needed. My experience with them was really good, they even taught me a lot about catalan culture and their complex political context.
I definitely recomend them if you want to feel at home when you go to Barcelona.