We had a family vacation in S. Sebastian (5 days, 6 adults). Overall, we are satisfied with our stay. The flat is located outside the center, so you'll need 3,5 km walk or take a bus (good connections). The flat is big enough for 6 people, but not well equipped. The dining table can fit only 4 people. Also, the amount/size of dishes is not corresponding. The bathroom is big, but is missing hooks for the towels. The toilet paper was not enough, the detergents mentioned in the description were missing. Moreover, the flat had the humid smell in the beginning and the blankets were a bit wet, so we had to hang them outside to dry.