What's your game?
Royal and Celebrity are great but the Ultimate Texas hold'em payouts have been modified (e.g., 4-of-a-kind pays 20:1 instead of 30:1).
I'm surprised you want to move from NCL. They have offered me better rooms (they gave me a Haven Owner's Suite for my next trip) and the admin fee was just added as OBC once I hit Sapphire. Royal, Virgin, Celebrity, MSC have all capped the comped rooms at a junior suite with the same play.
The only thing that Celebrity does better is the free play based on your past trip. But, as a UTH player, each bet is a max pay of 5k, so there is no upside for me despite getting 3K in free play each trip.