Yes, I became a diamond member last summer. I have since become a little remorseful about spending that money. In retrospect we would have still made diamond after the upcoming cruise, and since the Grandeur has no concierge lounge, Johnny Rockets, etc., being a diamond member has little meaning for that ship. We're returning to spreading our business around, hence next year's summer cruise being on Carnival. I'm done with trying to pile up loyalty points.
As for the Rockets coupon...it is gone from all coupon books now. For diamond and diamond plus they replaced it with a "buy one milkshake get a second one free" coupon. Most of the new coupons are only good if you buy something first. I am going to post a detailed breakdown on them when I return from the Grandeur.