So, 10.11.0 was Fine - worked well on both my MBpro and my old MacPro. Nice and snappy and no issues at all.
Yesterday, I installed 10.11.1 on my MBPro. I had not made a backup - I am an idiot lulled into a false sense of security because I have never had one single issue with any of the updates since, like, the beginning of the OS X era. (Except for some SMTP mail server problems at one point, a long long time ago.)
Yeah - this install? Not so good. It all seemed to work fine until it came back up, asked for my iCloud account password, and then showed me how truly borked my account was! All other accounts on the box work fine, by my account won't show me any files, applications, utilities. If any do appear, they won't start ("Missing or Incomplete" error message). If you find a Word doc to click on, it will open in Word, but you can't open word directly. This is a total mess. Safe mode doesn't help, so it's not some strange incompatibility. I think something somewhere is either missing or corrupted in the account that was used to do the upgrade.
Notes to self for the future:
- make a frikkin' backup: you're not invincible or particularly blessed
- Have an account set aside purely for doing installs, upgrades and updates. If it gets fracked, you're still in the game.