Wow what an experience for our 1st cruise where to begin. Beautiful brand new ship, loaded to the rim with great restaurants, activities and attractions. Being an adventurous family, we never took the Carnival excursions, rather we rented cars in most of the ports of call, which wasn't simple due to the distances involved but ultimately highly rewarding due to the freedom and flexibility this gives compared to the structured (and expensive!) nature of the excursion methods.
Jaime the veteran cruiser director and the rest of her staff are out of this world - energetic, friendly, funny, knowledgeable, patriotic! There were 4 main night shows, all entertaining and not too crowded if you show up on time (no need to reserve anything) + some playing performances + a commercial performances + the Dr. Seuss kids show. The Dive In Movies are great we saw quite a few and they provide comfy blankets if it's cold outside. We also went to the IMAX to see the brand new Magnificent Seven movie - great experience but pricey. Still worth it.
We ate breakfast at the Family Harbor and Lido Market - never crowded, never big lines, great service and selection. We ate lunch and dinner at the big dinning rooms - again great food and service. No lines if you take the select your own time option rather than the prefixed options. Elevators are too few in all 3 sections of the ship, they should have added a lot more with these many guests but it's bearable. The hamburger joint is great for late lunch or early evening snacks, solid 24/7 pizza joint too, you can also eat lunch for free at two of the paid for restaurants - the Italian and Asian ones - both were nice! My wife went to the spa and really enjoyed herself there.
We are a family of 5 with 2 adults and 3 kids (11,6,3) and we could not have picked or wished for a better room - excellent quiet and convenient location, very close to the Family Harbor break room (where free snacks, breakfast, cold drinks, ice cream machine (which did break down after a few days but there were others like in on the Lido so no big deal) are served. The room was quiet, comfy, spacious, with 3 big windows looking out at sea, one of which is actually the (massive) door to the balcony, which we used more for drying bathing suits etc. You get a king size bed for the parents (which BTW is high so you can store stuff underneath), a convertible sofa-twin bed for 2 kids, another Pullman bed (retracting from the ceiling + ladder) for the 3rd kid, 2 separate bathrooms (one shower with toilet, the other bath tab, both had sinks of course and some shelves) and 2 separate TVs. You can close off the kids beds with a curtain for separation. We also had a seating corner, plenty of storage space for everyone, tones of towels and 2 kid sized bathrobes.
Because we stayed at the family harbor we also received one free Night Owl baby sitter service for free, 2 big bottles of water and one bag of laundry for free. Maybe other cabins also get these perks, we don't know. Our friendly steward - Randell - an awesome person with many years on Carnival boats who exceeded our expectations in terms of service, availability and knowledge.
Hard to get rental car - it's not close - but you can get Uber to the eurocar stand it's a 10 minute ride. Go to the Calanques south of the city and to Cassis beautiful stuff. Gordes is another option but a bit far.
We only embarked at Piraeus having previously visited Greece in 2010.
We didn't rent a car since the ship docks right in front of the main attractions and you can take a hop-on-hop-off bus to Madina and Valetta. They also drive on the left side of the road like in the UK which takes time to get used to.
Easy to rent a car from Maggiore (now owned by Avis) they are located about a 10 min walk once you disembark. go to Sorrento then continue to Positano along the Amalfi coastline.
Rental shops are available right outside the port, go to Lindos.
Easy to rent a car from budget or Avis they are located right next to the free shuttle terminal.
Renting a car was impossible since the ship docked on sunday - serious bummer.
Easy to rent a car from Avis or Budget since they are right beside the ship when you disembark - great stuff! all destinations are doable in terms of distance and time - go to Pisa and then to San gemingiano. Skip Lucca waste of time. Be careful when returning to the port it's a bit tricky since there are several gates and internal roads and not all lead to the same cruise boat dock. Luckily the Vista is so huge you can spot it from miles away and its a good navigation aid.