My girlfriend and I had a great time at Maria's apartment, she was an amazing host.
Maria and her English-speaking relative met us in person to ensure a smooth check-in (even jumping into my car to provide directions to the apartment's otherwise tricky-to-find off-street parking). There was a bottle of wine, some chocolates and beers to welcome us upon arrival which was a really nice touch.
The apartment is kitted out with everything you need for a comfortable stay, including beach towels and a washing machine which came in very handy.
In terms of location, the apartment is less than a 5 minute walk away from a really nice beach and, whilst a 30 min walk/5 min bus/cycle away from the old town, is surrounded by great bars, food and amenities. The bar at the end of the street (La Cerveceria) has a nice local feel, really cheap wine and amazing pintxos. The area was quiet at night, meaning we slept well throughout our stay.
All in all, a perfect base for our trip to this lovely city.