Went off to Rome in September. Had a fine time, saw all the sites. Weather was good, but it was very warm and humid.
Here are some points--
--Took taxis all over the place because it was the best way to get around, especially if you can't walk that great like me.
--Stayed at Hotel Rosetta on Via Cavour. Decent hotel and room, but lots of stairs and no elevator. Only a few blocks from the Colosseum and the Forums. Some good restaurants in the neighborhood. Can have a nice evening walk from there to Trevi Fountain and Spanish Steps.
--The Pantheon now costs $5 to get in; one line for cash and another for credit card.
--I brought long pants and a long-sleeved shirt because I always read they would be needed for the dress code to get into St. Peter's and the Sistine Chapel. Turned out I was the only one. Everyone was wearing shorts and short-sleeved shirts. Women weren't bare-shouldered but wore shorts, or short dresses, and short-sleeved blouses. So a dress code doesn't happen or not enforced. Of course, you always want to dress decently.
Amalfi Coast--
What can I say about this. Not the best experience. Summer haze smothered the coastline and the beautiful scenery, so nothing to see there. Positano and Amalfi Town, unfortunately, are now world-class tourist traps. When you have tens of thousands of people crammed into small towns built for no more than a few thousand, it's not a good experience. Shops abound everywhere (mostly for women), with only a few people shopping inside them. Tourists just wander around looking at things, trying to find the charms of each town that are now too hard to find. On a hot, humid day in September, after an hour, I just wanted to get out of there. I took the boat ride down the coast instead of the bus or taxi. Though the coast road may be interesting, the views are covered up by the haze, but on the boat, you can see the coastline and all the towns along the way. The ferry is comfortable and not too expensive. To have a better time here, only go there in April or May. That's what Rick Steves does. The haze shouldn't be as bad and the crowds smaller. Any other time is basically a waste.
Sicily-- I spent four days here and it wasn't enough. Stayed in Palermo and Taormina. Rome Went down to Agrigento to see the Greek ruins on a hot and humid day. But I could only brush over the main sites, not enough time to really get into it. Driving around wasn't too bad. If you rent a car and use its GPS, don't simply take the route it chooses. Check other routes that may end up being faster. Again, just like everywhere in southern Italy, come in the spring for cooler weather.
Safe travels.
Tom