The apartment is very nicely presented, clean, neat and well equipped. The bed is very comfortable but the sofa bed is not so good, in spite of the topper, and the main reason not to award 5 stars.
Although it's away from the city centre the location is good, with allocated parking for a small car and cheap and easy public parking for a large car, there are excellent bus services into the heart of San Sebastian.
Javier was an excellent host, welcoming us to the apartment, giving advice on the locale and recommendations for places to visit, restaurants etc.