Fantastic views, excellent location and a faultless apartment! I have to agree with a few other reviews here when I say, if anything, the pictures don't do it justice. The flat is located at the far end of the beach, a 10-15 minute walk to the old town (I wondered if this would be a bit of a downside but the walk is actually a very nice stroll along the beach and the immediate area is very nice so it's hard to complain)!
I really can't think of any downsides to staying here and it really is the best AirBnb we've ever stayed in. The hosts were helpful and responsive (Adrian kindly sent us his recommendations for restaurants which was great). We'd love to stay here agin next time we're in San Sebastian and couldn't rate it higher!