Hi Joe,
We are working on functionality which can find difference between files of yours customized installation and etalon package of ViArt software. It may appear in some of the next releases.
Now upgrade doesn't touch content of the site, only database structure. So we don't include new payment systems, shipping modules and layout schemes into it. We are planing to issue all this modules as additions so you can add them into database only if you need. It will use our backup/restore database functionality from the next release.
WBR,
ViArt Support Team
In addition to customizing templates and files, I've found that the upgrade process does NOT add new content to the database. It merely updates the database structure.
I've reported this to ViArt Support, but their take is that this is apparently not necessary for them to do, as these are things users would customize.
That means that after their upgrade process, I do not have any of the new payment gateways added, none of the new templates are added, any shipping methods that have been added since my last version are missing, etc. Their response is that I need to add these things manually now. Doesn't anyone else see this as a problem?