re: Where to stay in Rome.

IMO, it really matters what's most important to you.

If I were going back to Rome I would stay in Trastevere, it has more of a residential neighborhood vibe than a lot of Rome. But that's what I look for when I travel, I want to hangout where people live, rather than the touristy places (obviously you have to hit up some of these like St. Peter's Basilica, the Roman Forum, the Colosseum, etc...).