Great apartment and location close to Sagrada Familia. We traveled with our three small children and were very happy with the apartment.
The apartment was extremely neat and clean. Comfortable beds and ample space for hanging out. Loved having the small balcony to sit out on after the kids were in bed. Always great people watching! Dani also had everything you would need for little kids - high chair, crib, a couple toys, even a potty :) No bathtub, however, just a shower (but he did have an infant bathtub available).
The apartment is on the "first floor" but it's really more like the second or third. There's an elevator but you have to go up a few stairs to get to it which was sometimes an inconvenience with our stroller and three kids, but we managed fine.
So easy to get to Metro and also the hop-on-hop-off buss stops. There are a couple parks on either side of the Sagrada Familia great for younger kids. The walk to/from the Sagrada Familia is full of restaurants and cafes with outdoor seating, shops, markets, etc. I was able to walk a couple blocks to a full service grocery store as well. We felt totally comfortable walking back to the apartment at night as well.
Dani was readily available before our arrival, always responding promptly to my emails. Would definitely recommend and stay again.