Overally our stay was pleasant, apartament was clean and the communication with owners was good and quick. The location is also an advantage, very close to the main railway station.
Although, you should be aware that the window in the apartament is basically blind- with some non-transparent glass, so it's really dark inside. Opening it is not an option, as the view is directly into wall and some air condition pipes, so it's also loud. Hot water in the shower ends up pretty quickly, so you need to watch it.
Summing up, if you don't mind the above, it's good option to stay, but we will look for something else next time we're in Bari.