Actually it's not "obviously" due to the transparency or blur at all. That's a common misconception and conclusion a lot of people jump to, even Canonical employees.
However a more detailed analysis of Unity performance shows that the main slow-down is an architectural problem. Unity and Nux are inefficient by design. And that is being worked on right now by the Unity and Nux developers. There will be a lot to look forward to in 13.04.
Actually it's not "obviously" due to the transparency or blur at all. That's a common misconception and conclusion a lot of people jump to, even Canonical employees.
However a more detailed analysis of Unity performance shows that the main slow-down is an architectural problem. Unity and Nux are inefficient by design. And that is being worked on right now by the Unity and Nux developers. There will be a lot to look forward to in 13.04.