Bologna, Italy -what neighborhood is best ?

I stayed in a hotel about halfway between the train station and the historic center (less than 10 minutes walk to either), at via del Porto 6. It seemed to be a residential area and was very convenient for day trips and enjoying Bologna. There was a supermarket around the corner, no restaurants or tourist shops that I can recall. I don't remember using public transport in the city at all.

Anywhere in the historical center.
Draw a one km radius circle with the center on Piazza Maggiore and try to stay there.
If you plan to take day trips by train, stay on the northern side of the circle somewhere between Piazza Maggiore and the station. Although anywhere in the historical center isn’t too far from the station anyhow.

We just spent two weeks in Bologna in the best apartment we've ever rented abroad. We've been renting apartments throughout the world for the last ten years so saying it was the best is saying something. Here is the link: https://mail.yahoo.com/d/folders/55/messages/ACq7tXQzbEzrXMoISAVi6JXwC8A
In case the link doesn't work its vrbo #474798
Its a two bedroom, two bath spotlessly clean, beautifully decorated, well stocked and everything you could ask for. Its located in the city center on via del pratello, 25. Quiet street during the day, however, at night it comes alive with many restaurants, bars, pizzerias and a great vibe (think Brooklyn cool) . Apartment faces courtyard so noise is not a factor. Comfortable beds. Great hosts who go out of their way to be available and make your stay unforgettable. Its a 5 minute walk to everywhere you'd want to go. Bologna is inexpensive so the two bed/two bath was completely affordable and gave us a chance to spread out as we had already been traveling for 5 weeks. Good luck with whatever you decide. You'll love Bologna and the entire area.

We stayed at Albergo Centrale in May of 2018. Was centrale to everything. About 15 minutes or so walk to train station. There's a local bus stop close by if you want to cut that time in half. Good breakfast, helpful staff. Only issue was inconsistent WiFi. We would stay there again.