My father and I stayed here for 4 nights and it was really a fantastic experience. Michela was waiting for us out on the street (arranged by Roberta and Oliver, who are both very responsive) and showed us how everything worked. Everything is spotless, appliances in bathroom, kitchen (we cooked dinner one night) and living space are brand new. Sofa bed folds down and is v. comfortable; main double bed reportedly is as well. The place is very secure as well - second level (with elevator) and a lockable iron gate for yours and one other apartment.
Location: excellent. Metro stn. 100m away, as are tram and buses; Colloseum is a 15 minute walk.