Gemma and Alex made the check-in process seamless, although I never got to meet them (they sent a proxy). Their place was clean and near the metro station, which was very convenient. Also there is a very thoughtfully-made book with suggestions of what to do in the area, including where to sight-see and eat. We loved all of the information readily available to us.
It was also great to be able to use the kitchen and make coffee in the morning. The balcony was a wonderful way to watch the sun set and rise each day. The building also has an elevator, which was nice for long days after carrying luggage around. The washer inside the apartment was also lovely, because we were able to wash our shirts and socks during the trip.
Some things to note: The bed in the 2nd bedroom is very small, smaller than a traditional US twin bed. Also, the walls are very thin in the building. You can hear other people talking, showering, watching TV, etc. and they can hear your conversations as well. This would not be an ideal place for travelers who are more interested in going out and experiencing the night-life, because the neighborhood is more family-friendly and definitely quiet.
The apartment was everything I could have asked for. Thank you for hosting us and Barcelona was a delight!!