My friends and I stayed at Cristina and Josep's place for a bachelorette week-end (we were 7). We all LOVED that place which is perfectly located (center, near Plaza Catalunya), huge, full equiped and decorated with lots of taste. And it was very clean !
Cristina and Josep welcome us so warmly that we immediatly felt at home. They accepted to buy all the food we needed for breakfast before our arrival, the fridge was full of good things and we just payed the price of the shopping.
I would really recommand to stay to Cristina & Josep's place, they are extremely reliable (which is not the case of all people in Bcn), nice and helpful. And the price is very cheap for service offered ! Don't hesitate !