The hostel is absolutely fine, not far from a the historical part of Bari. David was very helpful, gave me a map and advise how can get to the best parts of Bari.
It was a bit hard for me to find the place, but they tried to help with everything they could.
Also I was accommodated in a room with 4 young spanish or brazilian girls who thought it is a good idea to arrive drunk 4 am in the morning, turn the lights on and "talk" very loud. This is why I was slightly grumpy, however not the host's fault.
I'd like to thank you for everything.