This is a great apartment, everything matches the description.
The location is perfect - the subway is literally a few steps away, the Coliseum is within 1km, the centre (Campo de Fiori, Trevi, etc. ) is also within walking distance, although a bit further. We usually went into centre on the subway and then returned on our feet, or vice versa.
All the windows in the apartment overlook the yard, so it's very quiet and there is no traffic noise at all. The beds are comfy, so we slept great every night.
There is a heating system with a thermostat, and also air conditioning, although we've only used the heating.
We've loved the building entrance which is distinctively Roman, with marble floors and huge doors, with a charming vintage elevator.
One of the bedrooms overlooks a garden with a big orange tree, and every day we've watched a couple of large green parrots peck the oranges!
There is a gelateria downstairs and a pasticceria on the nearest street corner! A supermarket is also just a few blocks away.
The hosts arranged a transfer from the airport for us, for a very reasonable price. Fabrizio was very nice to meet in person. He met us upon the arrival, showed us the flat, and gave useful directions for all sorts of tourist routes.
All in all, this was a great trip for us, owing in equal parts to the Eternal city of Rome, and to this amazing apartment and its hospitable hosts.