I stayed at Giovanni's for a weekend in November. Giovanni could not have been a better host - he met me at the apartment, showed me around, explained everything and had prepared a wonderful guide full of tips on local restaurants, maps, etc.
The apartment is wonderful - it is exactly as shown in the pictures. If you are closer to 6 foot tall you may struggle a little as the entrance and bathroom are low ceilings but this is part of the charm of this traditional and beautiful palazzo.
The location is perfect - less than 10 euros in a taxi from Termini or a short journey on the 40 bus. A short walk from all the major sights, including Vatican City.
The nearby square is awash with wonderful and Roman restaurants and there are numerous cafes in the vicinity for breakfast.
If you want to truly experience Rome then I would highly recommend staying in this beautiful apartment.