hey, for anyone who is considering a fresh install (what I do every year) you could run into a few problems (eg. with mail because apple moved account settings and the script for fixing is deep in the system). I took a lot of time to work with the gm and the betas and put together a project for backup, restore, manuals (how to make the installer medium, solve the mail problem,...) and a lot of scripts to save a lot of time.
If anyone is interested you can check it out for free here:
https://github.com/tiiiecherle/osx_install_config
have fun with clean installing el capitan