We spent a full week with the family (myself, wife, and 15 and 11y old kids). Location is fantastic if you want to focus more on the beach than the center of Biarritz. Walking distance to Ibbiaritz, Milady and Marbella beaches. All of them offering food options, lifeguards and surf schools. Easy access to busses that go to the city (8min ride). Breakfast is fair for a 3 star hotel. Read a lot about issues with replenishment, but whenever we asked for something that was missing the staff was super kind to arrange it. Our room was big, nice beds and a balcony with sea view, which not only was beautiful but came in handy to hang wet clothes when returning from the beach. Lots of parking places available, also with recharging station if you need it.
Good restaurants at walking distance from the hotel.
If I were to point out some improvement opportunities Id say a shower on the outside before entering the hotel to get rid of the sand when coming back from the beach and maybe a small minibar to have some cold beverages in the room.
We would definitely stay in that hotel again if we return to Biarritz.