If you accidentally edit one image and replace it with a small jpeg instead of a large high res jpeg and you mirror your drives that large jpeg is lost forever. I had much the same scheme as you for years until I realised this problem.
Yes you are correct. In my case I never edit an original. Originals are kept in their own folder. I make a copy of all the originals which I save to an edit folder. It is these files that I work on. Worst case scenario is I lose a high res edit - but I still have the original to go back to and re-do all the editing.
I went to AllSync as I was sick of job errors during incremental backups (Genie Backup Manager) and having to rebuild the whole backup job (200,000+ files on my most common job) again and again. I just lost confidence that my data was safe.
This way is simple (no increments, no compression; exactly the same folder structure that can be read by Windows Explorer straight off). Is it foolproof - no, there are potential error points if you are not meticulous about the workflow. Does it have built in automation and redundancy - no. But it is a simple and effective (to date) solution that fits my needs.
