I've never ordered one either. However, on my last cruise, I attended one of the "Art of Entertaining" sessions. This one was led by the head dessert chef, who showed us some cake and plate decorating tips. I guess I had the image that he was going to do some fancy wedding-cake-type stuff, but alas, that was not the case. Basically he had a couple of round cakes with white frosting. Then he proceeded to pipe some frosting on the borders, put colored sprinkles around the edge, and stick a strawberry and some chocolate sticks on top. Voila - cake decorated. I could have had a V-8.
(By the way, sorry if anyone else enjoyed it! I don't mean to be negative. I just had a different expectation and wish I had learned something I couldn't already do.)
The point of this story is that later on, I saw a room service tray on the floor in the hallway. Sitting on the tray uneaten was a cake just like the one he decorated. I have no idea what kind of cake it was (they let people taste the cakes after the decorating session, but I didn't bother staying around).
Speaking of cakes....has anyone seen that "Good Eats" episode on WDW on the Food Network? It was on the other night and featured a segment on wedding cakes. Talk about fancy! Those were absolutely amazing. They said the most expensive cake they ever made was $15,000.