Also leave yourself a 10-20GB partition sitting empty, so you can install that OS without having to choose which existing-and-working thing to nuke.
There can still be issues here or there when Package 3.0 upgrades Package 2.0's dot directory irreversibly, but I haven't had much trouble; it happens that most of what I personally deeply care about are things like .emacs or .vimrc type files that don't work that way.
There can still be issues here or there when Package 3.0 upgrades Package 2.0's dot directory irreversibly, but I haven't had much trouble; it happens that most of what I personally deeply care about are things like .emacs or .vimrc type files that don't work that way.