I had a nice stay at Maria's place. The flat is perfectly located, 5 min away from la Rambla and Plaza Catalunya. The flat was clean when we arrived and, even though Maria was not there personnaly, she was always available by phone to answer any questions. You'll find find all you need in the flat to make your stay confortable.
The only negative point is the noise: really loud neighbours listening to music, listening to TV or talking late in the night (especially on weekends).