The installation does not work for me. I follow all the steps and then run '$ emacs' in the console and the old GNU emacs just pops up. Anyone got a clue what I'm doing wrong?

Edit: fixed it. It turns out that was an ~/.emacs file present which prevents Spacemacs from starting. If you did the cloning and $ emacs results in your standard GNU emacs, look for the file ~/.emacs and remove it.