My partner and I stayed at the apartment for 1 week. The location of the flat is better than expected! There is a la rambla (not the famous one) very close and there are plenty of restaurants! The beach was close as well and very clean, in contrary to the beach downtown, where you can find lots of waste... metro is 5 min walk away and it is easy getting to the typical sights of Barcelona.
Unfortunately there was construction work next door as they are building new houses.
The flat itself was clean and there was no problem with sharing the bathroom as Kathy is also very quick and actually was never in the bathroom, when we wanted to go in.
The sleeping room was for two people with 2 suitcases (1hand luggage) not very big, actually in my opinion a bit too small.
When you arrive Kathy asks you to sign a contract in Spanish... I was not absolutely comfortable with it but as far as I could translate it, it was non big deal... so far no problems ;)
All in all it is very nice staying there and the location is top.