We chose Carnival Vista because of reasonable prices and port-intensive itinerary. I'm writing this because I had seen so many poor reviews which made me apprehensive before we left. All in all, we (my husband and myself, seniors) had a great time.
We used Carnival transfers from the airport to the embarkation port in Athens and everything went smoothly. The port, itself, is a makeshift port to handle all of the people (i.e., set up with tents). Carnival, though, had things organized pretty well.
The ship is very modern, decor is not as fancy as some other Carnival ships. The gym was great - all new equipment and it was never crowded when I was there. There is a lot to do, especially for children. They have a large camp area and many areas for kids to play onboard. The water area with slides is very cool. They have a ropes course above ground and the sky ride.