Blanca's place is fantastic. It's apparently in an old theater, with a beautiful courtyard with a tree and fountain. You are very well insulated from the sounds of the rest of the city. It is also very convenient to many parts of the city, with most things like the Alcazar and Cathedral only about a 15-20 minute walk. It is also next to the Metro Parasol (the "mushrooms") which make for a great landmark to navigate back to as you explore beautiful Sevilla.
Blanca was also a great host, and had her friend Rafa waiting for us when we arrived. He stuck around the apartment quite a while too when there was a mixup with our transfer from Portugal. He patiently answered all of our questions too as he showed us the apartment at check-in. My wife and I would be happy to stay there again if (more like when) we return to Sevilla!