I have 15 cruises on Crystal, know much of the crew and they know me by name. I can assure you i have never gotten a space in a sold out tour or a better table in the restaurant. And the only reason we ever get our time slot in the specialty restaurant is because we tend to eat late, when it’s less crowded.
I was on SS a year ago and it was very obvious who got treated special. In fact once we wound up becoming friends with a couple who sailed 100’s of nights on SS (since we got to know them on a tour on turn around day) all of a sudden we were getting more preferential treatment and a much better location in the main dining room with our friends waiter, etc.