I didn't read when you are going, but just in case, make sure you factor in the heat of summer!
We did three days post cruise in Rome in summer and it was unbearable. By the third day, we called an audible and side-tripped to Naples, then Capri. (It was a tour company that picked us up in Rome, but I'm drawing a blank on the name.) It was still hot, but not as hot, and the boat ride to and from Capri was comparatively pleasant.