I don't doubt that the top floor flat is amazing. I was in number 5 on the third floor and it was barely big enough for one person. Actually its OK for one person, but there aren't many flats where you can sit on the toilet and touch the bed you're sleeping in, are there? It was cramped! It's a great location, but don't forget, the Catalans eat and drink late, so it can get noisy in the Rambla below.