We just returned from an 11 day cruise on Equinox--Rome to Rome, visiting Santorini, Athens, Istanbul, Kusadasi, Mykonos, Salerno (Amalfi Coast). In general, a lovely ship with good food and fine service throughout. No real problems at all, excellent cabin service, generally ease of access across the board.
First, you can easily take the train to Civitavecchia from Termini in Rome, but there is no way to get from the train station to the boat harbor except by walking and pulling your suitcases, about a 20 minute walk in what can be hot, humid conditions. Not the end of the world, but be forewarned. They hugely overcharge for the transport through Celebrity, but you can book a car or taxi from Rome for about half of their charges. We did take the train both ways, and they actually never collected our tickets on the way out, so we just traveled for free on the way back. Ah, Italy.
We like to travel pretty hard and see lots of things, and this trip was lovely but oddly a bit too relaxed with perhaps more luxury than we really needed.
Excellent cabin, quiet, aft, good location, great service.