We stayed for a week in August. The location is great - about 5 minutes from the Metro at Placa Espanya, and there is a bus stop just outside. It's within walking distance of the Magic Fountain and Montjuic, if you don't mind walking for twenty or so minutes.
It's an older flat, but it is in good condition, and everything inside works. There is a washing machine, so you can keep up on your laundry. The kitchen is well-equipped for making meals, although there are many restaurants close by. Check out the bull ring across from Placa Espanya - many good restaurants there!
We coordinated our check in and we were met at the flat. Everything went smoothly, and we didn't have any problems. It's a good value, considering the very convenient location, and we recommend it to anyone looking for a Barcelona escape.