GNOME3: The energy cost
I did a little bit of power profiling on my ubuntu laptop. I noticed that, when running gnome3, the videocard would get 60 interrupts each second.
Comparing idle energy use of my openbox desktop and GNOME3 this resulted in a difference (on average) of 1.1 W.
So, GNOME3 almost costs me 1 hour of battery lifetime.