Betty, you can count on Ngaire to help you save money for this once in a lifetime cruise! If a 4 day Diamond cruise (to wherever) will get you that on-board booking and past passenger discount, go for it! The Diamond is a favorite of mine, because it is different from the other ships, being smaller. I love the dining room, the balconies, the ambiance of the smaller size, etc. But I would prefer the Voyager for a long cruise like yours. Bigger closet, bigger cabin, better bathroom, curtain between sitting and bedroom, more dining venues, and more varied entertainment and public areas. So they are really not the same physically, but share the wonderful service that is a hallmark of RSSC in my experience. I would think the passenger demographics of the World Cruise would closely resemble that which I encountered on the Voyager shakedown cruise with many cruisers with over 100 nights on Radisson. Usually people start out with shorter cruises. The longer the cruise, the older the average passenger, but only in age numbers! On the Voyager shakedown (my very first solo cruise) I found the passengers much more relaxed about reaching out to others, as they were very frequent cruisers. Most people are not traveling with a group of friends, (how many "groups" can you get to do a world cruise?) but hope to meet them on board. Once when I was out on deck at the rear of the ship taking sunset pictures, a lovely couple just stopped me (for no reason) on my way back to the cabin and invited me to sit down with them (they were dressed for dinner, I was not). We must have chatted for half an hour about everything. He was a retired surgeon, and on board I met people from all walks of life, from academia, law, business, medicine, public service, and a few who were still in the working world. You wanted to know about the "atmosphere". I would say that yes, RSSC passengers are "normal" people, just like most passengers are. The difference about the people that cruise on this line (from what I have seen in my 10 cruises with them) is that they don't try to pretend to be otherwise!