Stayed for 5 day-break and it was just perfect. Host (Natalia) stood by for our check-in (she even provided some food in case We needed), as we were late arriving from the airport and showed us in a timely manner. Apartment is located just a 1 km away from Sagrada Familia (you can see the towers tips from the terrace which has an astonishing view of the sorroundings). Perfectly located with a bus stop just few meters away, Bus lines will get you there from either placa Catalunya (55 that can actually take you up to Montjuich) or Placa de Espanya (50). The apartment is just as it appears in the pictures, very quiet, completely furnished with everything you may need (and I mean it!), very clean and with completely separated bedrooms, although main bedroom bed size might be a little small for tall people as me. Wifi was fast and steady throughout the whole apartment. Please consider that it's a 5th floor-attic and serviced with an old style elevator that lifts only up to 150 kg, so do the math!
There are a lot of restaurants, cafeterias, grocery shops just few meters away from the location (if you don't want to travel), otherwise get on the bus (don't forget to buy 10-tickets set which will save you a lot of money).
Again, Natalia superhost provided some nice tips for visiting Barcelona during Sant Jordi day (23 apr local patron), I would recommend this location and I would surely come back if I had the chance.