My partner & I stayed at Carlos place in Bologna for 5 nights. It was fab. Carlo was not around when we visited but his friend Sergio met us & settled us in to the clean & tidy tavernetta.
The weather was unusually hot in Bologna during our stay & the tavernetta was probably the coolest place to be. The decor and features are as illustrated in the photos though it's magical just being there in the flesh. The wi-fi was a huge bonus too in addition to the numerous guide books and maps Carlo had in the tavernetta.
It was cool (temperature and style wise), very near to the best gelato shop and walking distance to many of the main attractions in Bologna including a huge selection of delis, shops, bars and restaurants. The neighbourhood itself was safe and we did not encounter and problems while there. A definite recommendation if you are visiting Bologna. Fantastic value for money and a lovely place. I could go on about it but will let you find out for yourself.