We had a good stay at Rambaldo's place, it is close to the train station and the city centre - very convenient to visit around.
Rambaldo was very responsive and helpful, he also sent us some information for places to visit and recommended restaurants.
The only thing to mind is that the house was slightly cold, as Bologna law has temperature limits (I am not sure if it the same for all accommodation and hotels). We were able to raise the temperature slightly, but maybe keep in mind if travelling in winter.