Exchange snapshot backups

Hi,

Way back in version 10, we had an issue wherein Exchange database backups often failed. It ended with us logging a support case, and by the time we got a response several weeks later, it came down to the following advise from Symantec:
We had combined a System State backup with an Exchange database backup. This was long problematic and we should separate them.
It also meant the backup defaulted to a "snapshot" backup, which meant it couldn't be used for RSG restores or similar. Which was a problem for us. And regardless of what other options you selected, you would end up with a snapshot backup when you combined Exchange and any other VSS backup in one.

The fact that one of our major recovery options (RSG) was unavailable to us and we were never warned about it rubbed us the wrong way, but in the end, the issue was solved.

Anyway, it's years on, and I'm still being asked to look at clients with random VSS failures, which all seem resolved by separating backups. It's at a point whereby I've just asked everyone to always create separate backups, then everything just works. Trouble is, I can't find anything in any "best practises" guide or similar detailing just what is going on and backing up the advice form Symantec support two? years ago.

Any advice appreciated.