The Lodging Team are fantastic, really easy check in and when we had questions, they were so quick to reply on email.
I think this flat would be good for a very short stay, especially if you are looking to have more of a party time in Barcelona.
We stayed for 2.5months. The flat is very noisy (the way the old buildings are, you can hear everyone on every level - And some people are noisy very late into the night / early morning). This made it very hard to work, which is why we were in Barcelona. The flat is also lacking daylight, although the pictures make it look very bright, you'll need lamps and lights on if you're looking to work the during the day.
Overall, we probably didn't make the best choice with location and this apartment for our needs. But The Lodging Team are great and probably worth asking any questions before going ahead and booking for a long term stay :)