If you can get Faster to the Fun: Get It! It is well worth the price. Picture long lines at Guest Services with one Carnival employee behind the counter waiting on cruisers, each with some kind of "issue". Picture standing in longer lines wrapped around the ship just waiting to get on a tender boat. Guess what, if you have FTTF, you don't have to. You get to just walk up to Guest Services and get waited on immediately, and FTTF folks don't wait in the line for a tender boat. They get priority boarding. We were one of the first cruisers on the ship and one of the first off the ship, with no wait through Customs during disembarkation.
My husband and I mostly cruise on Princess. I can tell you, it felt like there were more activities and people stayed active later on Carnival, then on Princess. The last Princess cruise we went on, it almost felt like the ship was deserted after 11pm.
We spend a lot of time in the casino on cruise ships. This casino definitely gave out the most free drinks to players than any cruise we have ever been on. In addition, they had great raffles and giveaways. They gave out money and cruises, not just hats and t-shirts. There are a couple of things. though that I feel the casino could improve.