If we are all being honest, the Butler is the most overrated thing in cruising. There just isn't that much for the butler to do besides bring food. That's why so many keep asking different variations of this question on these boards. It sounds cool, but not very practical. We had a butler at the St. Pancras Renaissance. He carried our luggage from the hotel and got us first on the Eurostar for our trip to Paris. That is a great service to offer. But I'm mostly hearing about non-stop candy and cookies coming to the room.
Seeing picture of M&Ms and gummy bears in my luxurious suite in the Haven doesn't do much for me. If I'm paying thousands of dollars for a great room and food, why would I load up on cheap candy? Just the opinion of one.