I had an amazing stay at Inmacdulada's apartment.
First of all, she is a very caring host, trying to enable the best stay possible. She provides you with tons of tips and touristic material and is open for all questions. Even though she is not very fluent in English and I am not speaking any Spanish, we came along very well.
Second, the room was much better than expected - very clean, with some basic breakfast equipment and very calm and private from the rest of the apartment. You will need approximately 15-20 minutes into the monumental area of Seville, but it is a nice walk at the river or through the alleys of the city.
I can highly recommend staying at this place as a cheaper and more personal experience than a hostel or hotel.