Well the wife and I are first time cruisers, scheduled to go out on the Conquest in May of 08. I chose Carnival because I wanted something out of Galveston, and my only decent choices were Voyager of the Seas with RC or the Conquest. We wanted to go in May, and the Voyager will be in Europe at that time, its last Western Caribbean trip is early April. So not only was the Conquest the one doing the trip when we wanted to go, it is also significantly cheaper.
So now you have the far cheaper rates, at the better time, and then add in the positive reviews I've had from so many Carnival customers and why would I not choose Carnival?!