Poor old Naples is a bit of a dump with grafitti and garbage all over. We had an interesting visit there in 2007 and didn't particularly want to see more. We'd already visited Sorrento, Pompei and Capri and a rainy morning gave us no incentive to go again to these places.
We'd been in Rome several times before and we originally had the idea to hop a train from Civitavecchia to Rome and visit St. Peter's. However, we heard about the two to three hour line-ups just to enter St. Peter's and decided not to go. Instead one of us took a wine tour to Lake Bracciano which was relaxing and interesting.
Venice is a magical city and we'd spent a wonderful week there 8 years ago. It was too rainy and crowded this time we didn't go ashore.