We really enjoyed our stay at Gonzalo's flat. The location is quiet and very close to the best family-friendly beach in San Sebastian. For our young family, the proximity to lots of playgrounds, a good supermarket, the funicular and the promenade around La Concha made our holiday. It's true that the hill it is on is steep, though the walk only takes 5-10 minutes from the bottom of the hill.
The flat is well appointed with a very useful kitchen, plenty of plates, cutlery etc and some useful supplies in the cupboards. It's great to have two, well-functioning bathrooms. There is no bath so young children will need to be showered.
The table on the balcony is a wonderful place to have breakfast and any other meal - the view is amazing. We can recommend watching the sun rise over the hill on the opposite side of the bay if you're up that early!
Gonzalo is lovely and very responsive also, which we were very grateful for.