I had a great three-night stay at Sarah's apartment. It is very centrally located (close to the Metro!) in a beautiful building with an elevator.
The apartment is just as described: clean, very quiet, and cozy. All of the extra amenities are there, including a washing machine, iron/ironing board, hair dryer, etc.
I didn't meet Sarah, but I met her friend Carmen who was very friendly. I highly recommend staying here and will plan to book Sarah's apartment again on my next visit to Barcelona!