The house is very good for 6 people, but perfect for 4. It is located 20 min walking from the Coloseum, 7 min walking from the metro station and 2 min walking from the closest bus stop. We never had problems with water temperature, central heat or anything. Fabrízio is very fast answering any question and he leaves you all the nice advices so you don't feel lost there.
Rome is an amazing city and , although the public transports aren't the best, you can always find a way to go to the apartment very easily.
If you are planing on a trip... don't think too much. It's a good choice.