This flat is very cute and a great place to stay. I loved the location in Gracia, there are a lot of cute places around and great streets all around as well.
The only "cons" would be there are a ton of stairs to get up to the flat (I hear this is common throughout Barcelona) and the key takes a bit of work to gain access to the building. We had to contact the host late at night for tips to open the door and then the next couple of times we entered it took about 5-10 minutes to get the key to open the door. That was just our experience, maybe we dont have the right touch!
Otherwise, this place is wonderful - includes AC which works great, a nice bathroom and kitchen and a comfortable bed and a working TV. We definitely enjoyed our nights spent at Isabella and Lucia's flat.