I hate the new trend with hostels of only staffing reception from 0900-1500 hours - especially when they say "Check-in begins at 1400 hours"! Outside that one hour window, you have to try and check in on-line, which is usually beyond challenging.
Also, the day before I arrived,. I received an e-mail from them all in Spanish and without a translator app on my phone, had no idea what it was about, until I got to the hostel only to find the e-mail was instructions for checking in since there was no one at reception.
All that said, the staff, especially the cleaning people were incredibly friendly and helpful. Hostel is close to Sants Justa train station and also close to most of the tourist sites. Great and quiet location, but other residents were incredibly noisy at all hours of the night - hence another reason reception should be staffed. Hotel decor and room are a bit dated and could be updated, but it was clean and comfortable.