All of the reviews are spot on regarding this apartment's location near to the Colosseum, Forum, and other classic sights. Although Rome is fantastic for sightseeing, if you want to have a true cultural experience, Frederic is your most important resource. Evident from his eclectic collection of prints, paintings and photographs on the walls, he is genuinely interested in having you enjoy an authentic introduction to Rome. Absolutely do not pass up his restaurant or gelato recommendations!
The apartment has super high ceilings, which gives it an overall spacious feel, and the furniture is classic older Italian pieces. The apartment is best set up for two couples, as the sofa bed was not especially comfortable. The kitchenette needs attention, but there is a good breakfast spot at the end of the street with a large coffee selection and a very funny waiter - so I would opt for that experience. There is an excellent wine bar less than a block away on via Cavour (#313?) that also has a limited, but interesting menu.
Frederic was very kind to arrange a very early morning taxi to the airport (48 euros fixed price). The Colosseum at first light is a fantastic sight!