This ought to be your worst option if you're trying to find a place to stay. When I arrived at the hostel that I had reserved, it was full. They permitted me to reserve and even confirmed availability on AirBnB with me, but when I arrived, it was full and there was no room for me. You can only imagine how frustrated I was if any of you were in my position.
The morning personnel was quite obnoxious and unprofessional. I received a refund from Airbnb and an apology for the inconvenience, but again, that wasn't the reason I made the reservation in the first place. They really peed themselves! Beware!! Take heed!
Berlin Mitte's Nena Hostel!