When I go to Grosseto (four or five times a year) I always book this Hotel. The rooms are equipped with air conditioning, WIFI, all the essential features of a higher rank hotel and are very clean. The building, remodelled in the centuries to host a Hotel, of course is not new but it is located in a very quiet small road, only a minute walking from Piazza Dante, where the Grosseto Cathedral and the Province Palace are, and from the Medici Walls, on top of which it is possible to walk around the Historical Center of Grosseto.
The service is carried out by a family and they all are very nice and serviceable.
Car parking is available and you can reach the hotel with your car. You only have to remember your car plate at the Hotel reception to get the Police permit, as within the walls car trafic is not allowed.
Pricewise the Hotel is affordable and if you don't look for luxury, brand new rooms and furniture or US rooms sizes I surely rocommend it. Very silent in the night....you will wake up with the Cathedral bells toll.