The good: Location, location, location. Walking distance to several good restaurants and cafes, 2 metro stations, many bus stops, and Las Ramblas. 4 bedroom, 3 bath was perfect for our family - all the adults had their own bathroom, and our daughter got her own room. The daily housekeeping was a nice touch.
The bad: Our apartment was on the "2nd" floor. You come in at ground level and have to go up 1/2 a flight of stairs to get to the small (2 person) lift. Then there is a floor for the laundry room, then 1, then 2. This isn't a deal breaker, but it's hard with a large group with luggage coming in, and my mother has a knee injury and needed the elevator which we couldn't take together. Also, the front bedroom (by the living room) - I think does not have a heating vent. It got very cold at night, but only in that room. After a couple of nights we left the door open and the heat regulated itself.
The good far outweighs the bad, and we would definitely stay again.