I would not hesitate to stay at Giuseppe/Michele's place on another visit to Rome. Situated in a quiet, friendly neighbourhood not far from Piazza Popolo, it is very easy to get into the centre either by Tram (#2 is a two minute walk) or by bus (Piazza Mancini is a 3 minute walk and there are many bus options.) In fact, after having too much fun in Trastevere one night we found ourselves having to walk home from Piazza Popolo and managed in just under 30 mins.
The apartment itself was very comfortable - exactly as described. We stayed for a little over two weeks and having a washing machine and wifi were great features. There is a nice grocery store about a 10 minute walk from the apartment, as well as smaller shops even closer.
If you are visiting Rome with younger children (I was there with a child under 10), I recommend the children's museum Explora - an easy walk or tram ride. It's a nice break from the crowds, and they offer some interesting workshops for the kids (my child did a "light-painting" workshop.)
I recommend frequenting the restaurants in the immediate neighbourhood. The food was good, well-priced, and every place we went to I found the staff to be very friendly and welcoming.