We've been cruising mostly Carnival the last 17 years. I feel we get the most bang for our buck and the treatment we get is awesome.
We recently sailed with another couple (from the Czech Republic) on the new Vista through the Mediterranean just before she headed to New York. The ship was very nice and met all of our expectations with a couple of exceptions...no glass elevators. My wife and I have always loved the layout of the Carnival ships so they are very easy to navigate. I think this time I expected something different. The "different" was the I-Max theater. Wow, very very nice but they need a much bigger selection of movies. Sci-Fi might be cool movies to see but it's just not us. "Sully" was great to see. The down side of having the I-Max was the loss of the glass elevators which I always thought were really awesome. They need to make the next ship (Horizon) long enough to accomodate both.
The buffet was ok...the Seafood Shack was good and the price no big deal but I missed the Indian food and the fish & chips (on the Glory). Sushi is a must! The taste bar and the outdoor BBQ were fabulous! The salad bar on the Serenity deck needs an awning but what a fabulous idea...loved the selection..would've liked it to be self serve but the service was great.