We stayed at Elena’s place for about a week and had a great time in Biarritz. The apartment was well-equipped, especially the kitchen. There was a big ceiling fan which saved us during the hot days. Location was good, 5 min. walk to the Grande Plage, and on a quiet street.
Since the building was old, there's no elevator, and staircase is a bit hard to climb with heavy items (luggage), but this is not a big issue.
There was an issue with the bathroom sink drain, which Elena tried to solve, but the plumber turned out to be irresponsible and due to holidays it was hard to find another one. Fortunately there was a second sink in the toilet.
Overall our stay was good and we enjoyed the time spend in Biarritz.