Slitherine

I noticed that when I upgraded the game with the latest patch the latest add on, Decline and Fall, was “preloaded” on my computer.
If I was to buy this add-on by download would I be getting just an activation serial number and a duplication of code already on my computer?
If I bought the boxed edition would I get anything additional beside a pretty box , serial activation number on a disk that contains the code already on my computer?

The download would be activating the game on your PC with a serial. It would also provide an installer that included the latest patch but you wouldn't need it. The boxed copy would do that and send you a boxed version in the post, so there are no additional benefits other than its a backup disk with the serial on that looks pretty on the shelf