I would recommend Fancesco's place to anyone. It is in a very good location and has a good layout.
There is a very nice market / grocery store about two blocks south of the apartment and there is a 24 hour grocery store / market near the Cipro Metro Station (about ten blocks).
I would recommend to ANY visitor - go to the Ottaviano Metro Station as soon as possible so that you can get a multi-day Metro / bus pass. The Ottaviano Metro Station has ticket counters that are staffed by people (or you can use the machines).
Make use of the Metro and the buses - this is probably the easiest and fasted way to get around Rome (you will still do a lot of walking).
For those of you who have not been to Europe before - bring your own wash cloths and / or bath/shower sponge. We have been to Europe a couple of times - so we are familiar with it.
Have a good time.