I saw a blog by another victim of OS-X 10.10
Just like me, he lost his disk drive.
Just like me, he was using PGP encrypted virtual disk drives.
It seems that Yosemite 10.10 blows up the PGP drives, making them unRecoverable when 10.10 tries to install. Self-damaging. This is a major flaw that Apple overlooked.
I have found that a lot of my old software no longer works. I guess some of it ran under the “classic” architecture, which is no longer supported. I’m betting here that 10.8.5 will be stable and useful for a long while yet.
…I never knew what I missed, until it was gone! 🙁