Thanks! Im still mulling all this ... I totally understand your last paragraph. Im not an IT pro but have been around computers of various sizes for just about half a century.
My business initiation to this sort of issue back when the world was young, was when our (large life assurance) company introduced desk top PCs with mini tape drives for backup and I insisted on a full dress rehearsal recovery to a bare machine. It did not go well. IT did not speak to me for days after.
As I said Im fairly happy with my main back (and recovery) process using ShadowProtect.
But I do need to do something about "off site" and also Im conscious that derivative images pose some additional challenges in recovery if one is forced to recreate work over a significant time period as many / most / all of the changes may not be documented on paper precisely or at all.
Havent heard of SuperDuper!, Ill look into it. One issue with ShadowProtect (which is very fast and also does copy open files) is that it only does entire drives so I was thinking of using robocopy batch jobs for the weekly image folder shuffling.