We stayed for a week in July 2016. we were greeted by Adrian and although there was an initial mixup on arrival, he was very helpful.
Gracia is a great area to stay in - this was our first trip to Barcelona and despite repeated warnings about theft, pickpocketing etc, we felt Barcelona was as safe as Rome, Paris or London.
We walked miles over the week we stayed here, discovering lots of areas - Gracia and Born were really interesting. There are so many things to recommend, that you will find what you like. The metro was great - buy a T10 ticket and take the time to walk to Plaza Catalunya or Park Guel.
There are plenty of places to eat and drink and all very reasonable - you don't have to walk far to find delicious tapas
The apartment is indeed compact and bijoux! However the air conditioning is great, the bed comfortable and the kitchen well equipped. We stayed for a week and had the apartment cleaned midway and a change of towels & sheets.
The terrace is great and although there was work being carried out on the facade of the building, it is probably complete now and it was not too much of an inconvenience.
We will definitely visit Barcelona again