Short review: Rent this place NOW. Don't think twice.
Long review: OK, so I can expound upon our experience. Myself, along with my wife and two young children stayed two days. The pictures match what you get. It is clean. It is organized. It is comfortable. It features little touches that make a good stay great (think: electrical outlets and a little shelf next to each side of the bed).
Elisa met us on time the day we checked in. She was very gracious throughout the entire process from the days before answering my question, to showing us the flat and to offering any assistance during our stay.
The location is a five-minute walk to the two towers, but you'll want to take the longer route as Bologna is a beautiful city to walk around.
The space and beds are comfortable. The shower and bathroom amenities are wonderful. Just take note, in the loft area if you do choose to have your children sleep up there, it can be loud as they walk around. Either that or my kids are just heavy walkers. :)
For two adults and two small children this flat was perfect. I can't recommend it enough!