You won't need to upgrade the box - new ones bought today are basically the same as the very first ones, except for a bit of tweaking to the circuitry - and there's a lifetime warranty for that. All the changes have been to the software, so once you've got that running, you will be up to date.
Check out the forum for additional items, such as silhouettes, airport and airways outlines, and logos which are constantly added.
Rod