The low rating is not directly related to the apartment conditions - which were overall good - but to the awful customer service:
1. Eva & Jacques are "invisible" people. You will never meet them. The only people you will contact are those front desk employees working in the agency. Most of the time they don't know about your specific situation and you might end up speaking to a different person every time.
2. The online customer area is as pretty as useless: you can report an issue but there is not guarantee that it will be solved. In this specific case, I have found the same problems already reported by other guests: the dish washer with broken door - that can really hurt you if you don't pay attention - and the ridiculous slow wifi connection. I reported it since I need it to work. I even showed the speed test: they recognised the issue but nothing was done since it a shared connection with several apartments and it would require to install more routers. Which they are not doing obviously.
3. When I had to move out, I booked a long term accomodation with them given the insane prices for short term in Barcelona. The experience could not have been worst. But this is not the place to discuss it.
I can only advice everyone to skip these lucrative agencies and rather contact real people who own the apartments and really are concerned about your stay.