Either option should work just fine. We use Joomla's Install Manager, where you can do a 1-click update if your subscription is active. If you choose to uninstall first, all the database configuration options will be left intact, so you shouldn't need to re-configure anything (except for any new features/options you want to take advantage of).
In general, we try to make things as easy and pain-free as possible, but if you run into issues, please let us know.
Thanks,
Alex