The apartment in itself is quite big, spacious and cutely furnished. You can see that the host is attentive to details as there are notes around the house with tips and reminders. The kitchen is well equipped and everything works. Bathroom is pretty spacious as well, we were 3 in there at times and didn't have a problem. Location is perfect, 5 minute walk from the beach Cote des Basques and a 10/15 min walk to the center of Biarritz. Very nice neighborhood, not noisy at all and a 2 min walk from a supermarket and a small but delicious pizza restaurant. Only problem for us was cleanliness as when we arrived it appeared as the cleaning lady forgot to put toilet paper and trash bags and the bed wasn't done as well. However I would like to believe that it was just this one time.
Sofa beds are really cozy and even when they are open they don't block the entrance to the kitchen and whatsoever so we left them open the whole time. I would also advise to not use the elevator as it doesn't work well and we got trapped in there for half an hour before the technician came to get us out, however if you do get trapped there is a number to call in the elevator and the technician will arrive even if it is the middle of the night so don't worry. It is only one flight of stairs so it's ok to walk.