Thanks for the comfort, but I was actually able to restore from an image backup I keep using ShadowProtect (AWESOME software) with a refresh of my important files from a copy I keep with Syncovery (more awesome software).

Back to the mirroring issue - have you done a full IO stall and wait stats run for 3-5 minutes to see how things fall out during that? If you don't have scripts for that PM me and I will get you what I use.

You do seem pretty knowledgeable, but perhaps Microsoft or other "sniper" resources could be what you need to decipher the issue here. If you go with Microsoft remember that the first thing they are going to ask you will probably be "are you patched to the latest build". So you might want to try to do that prophylactically - who knows, you might stumble across something that fixes the problem. Test first obviously... 😎