We had a very nice stay in this beautiful old roman appartment. The + : feeling of being in a real home, full equipment (from several tv to several coffee machines). To be warned : no clim, which can be hot in roman summer, but is part of the experience. Furthermore, plenty of large windows to get some fresh air at night.
The ++ is the location, right in Trastevere but not in the most touristy part of it, one step from Testaccio - means you can live and eat in Rome avoiding the summer crowds. Bus stop to Monteverde at the step of the building