We spent two months “living” at the Gothic House and thoroughly enjoyed our stay. The flat is very well located! You can walk to anywhere in the city, or to the nearby buses and metro lines. The five floor walk up was tiring in the beginning but by the end it was just part of what we did. The rooftop patio on nice days made it worth it! Isa and her team are very responsive. We had some mechanical and other problems during our stay and the team resolved them rapidly.
There were a few downsides described below, but we would definitely stay here again 1) the front of the flat is noisy late into the night—because the flat is as described, “surrounded by bars and restaurants”. Bring ear plugs if you need to use the front bunk room for sleeping. We used the bunk bed room as an office because there were only two of us. When I had meetings in the middle of the night because of time zone differences with my company (1-5AM Barcelona time) the room was often VERY noisy and even then I had to do my meetings with AirPods so my colleagues on Zoom were not distracted by the noise. 2) while the flat has all of the modern furnishings you need, the building, and subsequently the flat, is old—with accompanying quirks that we figured out how to work around or live with (doubt this would matter for a short stay). 3) the 2nd bedroom is really an extension of the main bedroom with sliding door dividers where you have to walk through bedroom 2 from the main bedroom to get out into the living area. We did not need to use them, but if you are looking for more than visual privacy between the two rooms, this might present a problem.
In summary, because of the great location and because we are only 2, we would definitely stay here again!