Overall it was ok, but I wouldn't recommend for a long stay.
First, I didn't appreciate that they didn't tell me the water heater in the shower broke after I arrived even though they knew before. They fixed it but it took 2 days in which the water were too cold even for summer.
Other than that, that sofa-bed gets really uncomfortable after several days. The fan helps, but only if it's on you (and loud) and there's not a lot of breeze coming in. There was also no set up to make hot drinks (coffee/tea) which is necessary for a long stay. The cupboard smelled weird and the apartment was not clean when I arrived. The floor was dirty and I doubt that the surfaces were cleaned.
The location is fine (the grocery downstairs is very helpful), but it's not convenient if you need to travel all over Barcelona. Overall, for a long stay (more than a week), I think there are better options for the value. But for a week or less it's fine.