Stayed in Dax on the way down to the Soth West of France this year as part of a tour. We stayed four nights and tour from there.
We did not book in advance but turned on spec. Its a family run hotel and Michel and Aline and very attentive and helpful. The rooms are basic en suite but clean and comfortable. The restaurant was excellent and the pool very inviting after a days touring. Nothing was too much trouble.
I understand from Michel that he wants to reitre and is putting the hotel up for sale so I hope if that happens it doesn't lose its local French charm. More