Comment 7 for bug 1281368

I don't know if there is any value now to note that the intention was to use 0px & it was generally well received for the short time it existed.
https://bugs.launchpad.net/ubuntu/+source/light-themes/+bug/733233

The negatives were laid out here -
https://bugs.launchpad.net/unity-2d/+bug/733431