I went alone for a business trip (medical congress).
Host: very helpful, welcoming and discrete. He lives in the house with an other charming person and a joyful little dog (that has never barked once);
Flat: my room ("large room") was indeed large and equipped with air conditioning and TV. It is also very quite, but a little dark because it has only a small window. The flat in general is very clean. The toilette has to be shared, and is a little bit "old-fashioned", but acceptable (and cleaned every day);
Neighbourhood: residential neighborhood, walking distance from "sants" station and plaza Espanya, with a large supermarket on the other side of the road and many more bars. I haven't seen any "bad" face even by night.
Would I reccomend it? I would :-)