We have stayed at Simonetta's place for 6 nights and found it a great experience. The place is well equipped, clean and quiet. It is located about 20 min stroll from the main sites of Ancient Rome, right next to a little park with great views on Rome and the special keyhole with the view on 3 countries. The immediate are is quiet with a short walk to cafes, shops and public transport (maybe a 5-7min stroll). The perfect accompaniment is the host - Simonetta - who is a fantastic host. She is very helpful, friendly and quick to respond to any requests or provide information.
While we were there the weather was on the warmer side so it didn't bother us much, but the fairly low water pressure in the shower means that it took a while for the water to heat up.
In general we thoroughly enjoyed our stay at Simonetta's and would recommend it or stay there again.