Staying at Martini's was the best choice we could've made. The place is exactly like in the pictures, it's very clean and spacious, it's 10 minutes away from the center (by foot) and the neighbourhood is very quiet and nice.
As for Donata, I have to say she was the perfect host. She's kind, warm and friendly and you can rely on her for anything you might need. She also gave us very good instructions as to where we can eat the best pasta and what we should visit, and she left us coffee & some snacks for breakfast, free of charge.
Donata made our staying in Bologna very pleasant, I strongly recommend her as a host and we would not hesitate one second if we were to stay at Martini's again.