We had a great time at Columba's place.
First of all we loved the breakfast (freshly squeezed orange juice, fresh fruit and granola - we declined the toast because we had already eaten enough with that).
Columba also has a wonderful personality, she answers all your questions and even tells you about events you didn't even know were there. (We actually got to see a free Gloria Gaynor on the beach due to her).
The apartment is on a hill but we didn't mind the walk, and you can easily take the bus to lots of places. Our car was also safe in her garage so we liked that too. Anyway, wonderful personality, nice flat and so on, we can recommend it! We would book again if we come back to San Sebastian.