Great, quiet location in the heart of a locals neighborhood across street from a big indoor farmers market and walks ranging from 15-30 minutes to major sights such as La Rambla, Le Segrada Familia, La Boqueria Market, etc.
While Casa Cosi does have central air, it was not strong enough in some of the bedrooms, making it difficult to sleep. I left a private note to the host about this after our stay, and suggested they purchase floor fans for the apartment.
Other than the air conditioning issue we had, highly recommended staying here as we enjoyed the location very much!