The Olive Tree was a lovely spot to explore Bari and Puglia! The staff made me feel right at home and provided suggestions for restaurants, transportation, and spots to visit. I didn't make it to all of them, but the ones I did were great. Likewise, I took advantage of one of the day trips they offered (to Alberobello and Polignano a Mare) and it was fabulous!
The location is close walking distance to both the old town of Bari and the Central train station (5-10 minutes to each), and the staff helped me out with the train schedules and routes as needed. The location makes it a quick, easy trip to the airport and other towns in the region.
I stayed in a private room and it was GREAT for a hostel single- large, sunny, clean, and with access to the balcony. They do have VERY specific check-in hours during the winter, which is something to heed if you're headed there in the off-season. (I was aware before arriving, so I planned accordingly.)
Breakfast was nothing to write home about, but was sufficient (cereals, breads, jams, coffee) and left me room to eat all of the delightful things Bari has to offer. The kitchen is the main common space, and proved to be a good place to meet other travelers staying the hostel.