Fantastic location, all located within 10 minutes of the old town, train station and bus station. The flat is bigger than it appears in the photos and easily accommodated three adults and one child on our trip.
Very clean, with all the amenities you could need, along with some local cider which was a nice touch! Iker's wife met us for check in and was very friendly and helpful. They set up a cot especially for our son, along with mattress, sheets etc.
The balcony is huge and is a good little sun trap. I would definitely stay here again if we return to San Sebastian!