We had a lovely time staying at the house. It was quite chilly especially at night but very beautiful, we loved all the tiling and the gorgeous bathroom, and had a really nice evening up on the roof terrace. The location is absolutely fantastic, so close to the main square but in among the tiny old streets of Santa Cruz. As others have said there isn't much privacy - if you have your lights on in the evenings people can see through the blinds into your room from the room opposite or the landing, and you can hear everything going on in the rest of the house. However there is very little noise from outside. There was no one to greet us when we arrived which was fine as there was a key left for us, though when we've stayed at other airbnbs we have been made to feel more welcome - shown around the property and given tips on the local area etc. The bed is very hard which suited me but not my girlfriend, so perhaps look at the other double room if you prefer a soft mattress!
I don't mean to sound negative, just pointing out all the ups and downs. Overall we would definitely recommend staying here - it is a perfect representation of Seville itself - beautiful, full of history, a little chilly in the winter but charming enough for you to overlook that!