We had a great stay at Wilko's apartment for a few days in early April. Wilko's apartment is a little way out from the centre (near the Sagrada Familia) but Wilko was very helpful in providing info on how to get there from the airport. This also meant that we walked in to the centre each morning and took in lots of the city that way. The room is a good size and has everything you need and though the walls are quite thin, this isn't actually an issue as the neighbourhood is quiet.