The location of the apartment was great. Communication was good. Check in was simple, and Guille was very good at explaining the details. Holger's place would be good for a group of friends or a family with kids. When planning to stay here, sleeping arrangements need to be considered in advance.
The two main bedrooms have a very good size. both would be good for couples. The 'bunk' bed in one of the beds would be suitable for older kids, but not for young kids, nor adults, as the ceiling space is too small to stand up. The third bedroom was tiny and without exterior windows. it had a double bed, however the bed occupies the entire 'room' space, and there is absolutely no space left for leaving a suitcase or anything. The room has no ventilation, so one has to sleep with the door open if the weather is warm.
In addition, the apartment has couple of sofa-beds in the living room for additional people.
Barcelona's city tax (2.5e per night-per person) and additional cost for late check-in should be taken into account as they add up to the final cost of your stay.