Fiorella's apartment is absolutely lovely. One of our favorite stays in Italy! It's beautiful and charming and in the perfect location, just steps from Piazza Maggiore! We didn't have any trouble with noise at night and slept fine, but if you're an extremely light sleeper, I can see that being in a busy area might be an issue, so just be aware. And it has several sets of stairs, one flight from the front door to the main floor, and one flight up to the bedroom/bathroom, so it's definitely not handicap accessible.
Fiorella is very quick to respond and communicative, and the one issue we did have she fixed immediately. We HIGHLY recommend her place and would love to stay there again if we ever find ourselves back in Bologna! Absolutely one of the best Airbnb experiences we've had.