Comfortable, very conveniently located, 1-bedroom flat with everything one needs to spend a week in Barcelona, including cooking meals and doing laundry. Sarah and her son are very responsive and helpful.
Just a note of caution: there's an elevator to the 5th floor, but you will still have to walk up another 20 steps to the flat and it can be dark at the top. There's also a step up from the living room to the bedroom.
I would stay here again!