We stayed in Rome for 5 days and I must say that after a while it becomes exhausting to see historical places everywhere you look. Of course is a must to see all the places Rome is famous for (Coloseum, The Vatican, Fontana di Trevi and so on) but I think is worth also to take the time and just take a walk on the streets of Rome that are not touristic and to feel the atmosphere of the city.
Unfortunately the food is not that good as expected, especially in the touristic places. We enjoyed our meal only once when we went to a restaurant in Trastevere that was recommended to us by an Italian and here the food was great and also the service was nice.
Overall, Rome is a city that must be visited at least once in a lifetime but I think it is a good idea not to make out of this visit a marathon in which you just go and check out all the known places of Rome ... I think it is nice to just take the time and enjoy its spirit :).