Stephanie and Joan are excellent hosts. They were always there to answer any questions and the apartment was very clean and had pretty much everything you would need. There is also an excellent view over the city. The only downside perhaps is that the area is hilly and the apartment is about a 15 minute walk from the metro. Having said that there is a bus stop right near the apartment and buses run very frequently and are excellent. I would often walk to the metro going out as the walk is downhill and take one of two buses to get back. Transportation to the center is easy and fast whichever way you do it. One day I simply walked to the Sagrada Família in only about 40 minutes to give you an idea.
The area itself is very nice and quiet with some parks and you can walk to Park Guell in about 15 minutes or take one of the buses a couple of stops. You can also easily get to (I walked) the lively Gràcia district.
All in all I had a very pleasant stay and thought it was good value.