aura glass
I tested GNOME's glassy new look - and it's simply spectacular
I installed Aura Glass, opting for the full Monty of features. I did find a noticeable hit on performance; however, I was running GNOME as a virtual machine with only 3 GB of RAM and 2 CPU cores. Give it at least twice the amount of RAM and cores, and you'll hardly notice it (which is impressive, given how much blur it adds).