I was searching for the suspend button in Gnome 3 and could not find it, even though I knew it was enabled when I logged into Unity and was able to suspend the same laptop..!
Appearently it is hidden (a bit).
This is the top right menu in Gnome 3 by default (without suspend options)
If you press “alt” while this menu is open, it will show the suspend button (with the pause icon):
So now I can suspend my laptop again!
Happy energy savings! :-)