The experience was really great it was my first experience with Airbnb and it exceed my expectations, I am really sure it would be difficult to improve it.
Everything was really clean , the apartment was great for two people, but I think that it would also be fine for 4. Massimo facilitate us to leave the luggage before the "official" hour to arrive.
We did not make a big use of the apartment, we had breakfast, lunch and dinner outside, but you will have anything you may need there.

The apartment location is great, between the historical center and the train station (250 m). We traveled to Florence on Saturday and it only took as a few minutes to arrive.
Bologna is incredible, really really nice, I encourage everybody to visit it. I think it is in the same "league" than Venice or Florence with the advantage of being not so crowded.