Debora is a great host, very hospitable, communicative and responsive. Her flat is spotless, fully furnished with all the necessary amenities and well positioned - a 30-minute walk to the Colosseum or several bus stops by bus 87, which stops just a few metres from the building. The bus also goes to Vatican and Castel Sant'Angelo. The city centre is just six metro stops away (Line A). However, three central stops (Repubblica, Barberini and Spagna) are closed due to some scheduled works, but you can always catch bus 85 from Termini Station (where Metro Lines A and B intersect).
I'd definitely recommend Debora's place :)