I went on a RCC in 1999 on the Majesty of the Seas. An older ship from 1994 I think. I thought the trip was ok, but not fabulous. Mind you, this was my first cruise, so I could say the same for say Carnival. I guess I'm just not a cruising person.... I was bored outta my mind at times (during the day). I'm not on to sunbathe, swim or go play bingo (everything for me was so expensive given that we had to pay in US dollars making it extra expensive for us)... and we had to share dinining arrangements with three other couples (and they weren't the friendliest type to 'our kind', if you get my drift)... Felt very alienated and isolated on that ship... and after two days, I was just bored of the ship.
Loved the ports of call though... Found getting off the ship and seeing the islands were great.