We booked one night at Sarah's apartments on the same day as we missed our flight, so we needed a place to stay for 4 people. Although it was Sunday and Sarah was not in the city, she responded quickly and arranged everything very efficiently, so we moved in two hours after the confirmation.
Apartments are not very large but have everything you may need. It is located just 3 minutes away from the Hospital Clinic metro, and about 10-15 minutes walk from Passeig de Gracia.
Very good option for the value!