We spent just one night in the flat but it was all fine for us. Is a little bit small for 4 people but ideal for 2. The apartment was very clean. From the flat is just a small walk to the 2 Towers and in less than 20 min walk you are in the Piazza Maggiore. There are many public transportation stops around the corner.
Alessandro was super nice with us and always responded our messages very fast. We can recommend his flat for anybody visiting Bologna. Thanks Alessandro!