Alex was really helpful, especially during the check-in process. We arrived late (22.00) and although she could not be there to let us in, she arranged for someone to be there to give us the keys and tell us all we needed to know.
The location is great if you are looking for a central place that allows you to reach different sights quite easily. One slight drawback was that it was a bit noisy during the night; some neighbours from nearby buildings were chatting loudly as late as 2am for example. This was only relevant because we had to sleep with the window open due to the warm weather, but in all honesty it did not bother us much. That being said, I can imagine how someone with a different schedule (e.g., a family with kids) might be more bothered potentially.
I would certainly recommend this place, especially to groups of young people visiting Barcelona.