We loved our stay at Javier's place. It was just what we wanted. We arranged for Javier's taxi driver friend, Señor Torres, to pick us up at the airport. Otherwise, I think it might have been difficult to find! The stairs are no problem for a reasonably fit person, and having smaller bags helped considerably. We appreciated Javier stocking a few groceries for us ahead of time, but really there are several shops close by. The apartment is bright and airy. The plaza is full of activity and it is a relief from the noise and crowds of the city.
It was a bit noisy on the weekend, but it didn't keep us from sleeping. We were able to connect to the internet, although it took several tries with my phone for some reason. We didn't find any instruction booklet for the apartment, but the coffee percolator, washing machine, dryer and gas burners didn't take much but common sense to figure out.
There were three in our party, so the place had plenty of space for us. The closest metros are Diagonal (10 minute walk) and Fontana (15 minutes?) I would recommend getting a detailed map of the Gracia area because there are so many great streets and squares to explore and a lot of guide books don't include this wonderful neighborhood.
Although we never met Javier in person, he was easily reached by text or telephone. I look forward to staying here on my next trip to Barcelona!