Summa summarum of the eternal city:
Good: The ruins, Colosseum, catacombs, basically anything antique, the churches and cathedrals and basilicas.
Bad: Pizzas were underwhelming, food in general underwhelming; camera ban in all the interesting places; long, long lines to certain places (but it is hard to really blame anyone for that)
You can't but help feeling sorry for Rome. After staring off by showing you its wonderful ancient monuments and sculptures, it has set itself up for disappointment by itself being an impossible act to follow. Because the history of the city completely overshadows the city itself, it is almost like one feels bad about not being amazed by the non-historical parts and wants to pat Rome on the shoulder, saying that it should just concentrate on the fantastic historical parts and probably forget about everything else.
A few observations:
The Vatican, besides bringing a ton of tourists, also bring out the sick, the poor and the mad like no place else. Beggars, a man lying next to the Vatican walls talking to himself, cripples... It has probably been like that for as long as the Vatican has existed.
Things just pile up. Everything in Rome is built on something that was there before. The Colosseum was used for building material; the bronze in St. Peter's came from the Pantheon. The whole city has that "lived in" feeling, with parts being endlessly recycled, moved, built up and torn down, layered, excavated and filled in.