Buggy Mac OSX 10.9 Mavericks update

A word of warning: Updating from Mountain lion to Mavericks is by far the most buggy process I have ever seen from Apple. At times the installer quit in the middle, My time machine volume was not recognized, network settings are lost, ...

Make sure you have multiple backups and plan some downtime. On the plus-side Homebrew and my Python-packages all survived. Just make sure you use pip with a virtualenv or the --user option.

Good luck.