The flat was clean and well-presented and it had everything we needed, including a perfect location near La Concha beach and the Old Town. There was no much natural light inside, but it wasn't a problem because we didn't spend much time indoors during the day. The key collection was at a different location. The staff of the managing company was really helpful and friendly, both in person for the key collection and on the phone.
The only small inconvenience was that we had to dispose of our own rubbish using the nearby street bins as part of the checkout, but it was an easy thing to do.