My husband and I spent a very pleasant week in this flat in February. Communication with the property manager and owner was smooth, they accommodated an early check-in, and we received detailed instructions on everything in the place. Getting two sets of keys was a real treat! The flat was comfortable, attractive, and reasonably clean, the lower level is bright and airy, and the location is surprisingly quiet for Barcelona (the narrow street is blocked to through traffic, but there's foot traffic and people hanging out on patios talking through the night, par for the course in Spain). We appreciated the laundry, and that there was even some laundry detergent in the flat. I imagine that the bedrooms can get hot, and there is little air circulation (especially when it rains) in the main bedroom which has skylights, but others say that the air conditioning works well and I'm certain I would have been given a fan had I asked. Luis's recommendations for dining were excellent.
The location is fantastic, just off the top end of La Rambla in Gracia, with easy access to lots of good food and metro. We've stayed in four parts of Barcelona, and this was our favorite location. If you want to eat at Berbena, make sure to book well in advance. There are plenty of other wonderful restaurants right by the flat that are easier to get into; Tangana and Santa Gula were particularly good. Origo Bakery is another place worth visiting, and the gelato across the street is lovely.