I booked two nights instead of three, and booking an additional night was easy and not a problem. The first night we were in a different room as booked, with a private bathroom. Second and third nights we were switched to a larger room, but shared bathroom, which is what we paid for.
The rooms were clean, and mostly comfortable. The rooms are good for sleeping in, if you plan on spending most time outside. The balcony's were nice. The shared bathrooms seemed newly renovated and modern. The hotel overall was not modern, but it gives a nice feel to old Spain. The elevator was fun too, old fashioned. The staff was friendly and accommodating.
The only complaint we had was that the second floor and next door was a college, so later into the morning, the courtyard was full of chatty students. So if you sleep with the balcony windows open, you may be bothered.
The hotel was in a nice neighborhood, walking distance from all our favorite restaurants and the metro. Only a short metro trip to the beach.