I have been on both ships (before the evolutions of fun upgrades)
There are some subtle differences between the Elation and Fascination. The Fascination has been retrofitted with balconies, while the Elation is still more or less the original configuration.
Secondly the last 2 of the Fantasy Class - Elation and Paradise had some minor changes as new builds. They had the lobby bar as a new build, when the rest of the class had some sort of sculpture that was several decks high (these have since been removed). In addition The first six ships were equipped with owners' suites at the end of sports deck (there are 2 doors marked "private", and do not show up on the deck plans. I guess the Carnival executives needed a place to say when they tried their own product)
The owners' suites were removed and that is where Camp Carnival was placed on the Elation and Paradise.