We think Andrea's apartment is good value for money. It's comfortable and not far from the centre (not in the very centre, though). It takes about 15 minutes walking to Circo Massimo and 20 to Colosseo. Plus it's close to a metro station.
The only thing we missed was some sort of livingroom with a sofa or something, but you can perfectly do without it for a few days.
Andrea was very nice and flexible about check-in time.
We would totally stay at Andrea's again.