We visited Seville for four days and had a wonderful time in Tomas and Mila's apartment.
The apartment itself is very clean and well furnished. Their organization is incredible: The material that they have prepared to help and make the guet's visit better puts to shame most travel agency's work.
The house has really everything that's needed (even an iron), and is very quiet, but at 5-10 minutes (by foot) from the Cathedral.
Really recommended!