We had a lovely stay at Rossella's. She was very friendly and welcoming and gave us lots of recommendations for places to eat, to visit, etc. It's a bit further away from the city center (close to the train station though), but in a proper Italian neighbourhood away from tourists.
When we visited it was unusually hot for the time of year and an aircon would have been a bonus, but we made it work with the fan.
We really enjoyed our brief stay in Bologna and can definitely recommend a stay at Rossella's.