On Carnival about the only thing you get will be priority boarding....and a larger room.
Do not expect the butler service you find on NCL or RCL's concierge service. I do have to admit that it has been over a year since I was on the Pride, but the Cat 11 there provided no additional perks.
My son really enjoyed the Butler service on the NCL Star and really wants to cruise on them again...after all he would go down and get him grapes and french fries to dine on