My family and I had a lovely stay at Sito's flat, which was light, stylish and well-appointed.
It's on a busy main road, but there's an underground car park opposite, so we were able to park our hire car there while we got our luggage in.
It's three flights up (although there is a small lift).
There is air-conditioning in the living room-kitchen area and in one of the bedrooms, but not in the second bedroom, which we found a bit warm at night.
We liked the local neighbourhood of Sants - particularly the small square of Place d'Osca, where you can find the wonderful bar and restaurant Terra d'Escudella.
The Placa d'Espanya and Barcelona's concert arena are a five-minute walk away, and the Hostafrancs metro stop is right outside. Buses to and from the airport (the Aerobus) stop at Placa d'Espanya.
There are plenty of places to buy food nearby, with Hostafrancs market just down the road, and a couple of supermarkets and bakeries.
To get to the Old Town is a 30-minute walk.