When I arrived Carlo showed me the apartment and had even arranged to have a hairdryer for me during my stay, he checked on me during my stay to make sure I had everything and was very easy to deal with.
The Tavernetta is a great place, it is quiet, safe & charming. The location is great for exploring and the courtyard is very pretty. The apartment is large and has most everything you need for a short stay. Other reviews mention the dampness from the well but this was a non-issue. There is a slight smell but I think it may be more from the brick ceilings than the well, in either case the dehumidifier negates any issue.
I would certainly return the next time I am in Bologna.