Maria's stay was perfect. She met us on arrival (communicating appropriately to confirm time). She provided great advice and even helped make dinner reservations.
The house was clean and well stocked with whatever you might need.
Location was on a quiet street but really close to the city center. The entrance is on a smaller street. If you are more than normal concerned about safety, you might find the small street uncomfortable. However, there are people on the street at all normal hours (and small alleys are typical of Bologna).
I would definitely stay again.
If you do stay at Maria's, pay close attention to her food recommendations. You want to eat at every one of them.