Rosa's apartment is very well located, walking distance to places like Sagrada Familia, Old Town, La Rambla, and the Gothic Quarter, while still being away from the hustle and bustle of those popular sites.
The apartment was very clean and comfortable - a nice place to relax at the end of busy days. Rosa is an excellent host and along with her brother, provided lots of useful information for navigating the city, as well as being very responsive to all inquires during the stay. I would not hesitate to stay there again if I return to Barcelona.