It can't possibly be free, so is the added cost worth what you get? It is to us, so we're going. Like you, we love to cruise, and RC is our favorite cruise line. We're bringing the average cost down by booking back to back cruises on the same ship, in the same cabin. One week with all the fun plus BYU, followed by another week with ongoing fun.
I've actually wanted to try out Navigator of the Seas for some time. It has a different layout than others and offers a little different experience so I was really glad to learn it was this ship.