Haven't done the QM2 [yet] but have done all the other large class ships. CCL, RCCL, Princess. Have also done ships as small as 17000 tons and smaller yet, I think.
Large or small, makes no difference to me. Cruises come in 3 flavors, Good, Better, and Best
Good-One I've done
Better- one I'm about to do
Best-one I'm doing