The Apartment is perfect, spacious comfortable and centrally located. We walked everywhere from here, The Pantheon (literally around the corner), Vatican City, the Colosseum, the Trevi Fountain and the Spanish steps. Claudia accommodated my request for and extra bed.
Would totally recommend staying here on the proviso that you have no mobility problems as there is no lift and you need to negotiate a substantial ascent on foot and you check in before 2000 to avoid the rather excessive 50 euro check in charge.