It looks beautiful in Windows and OSX.

It looks less awful than the current theme in Linux, thanks to the menu button (which usually occupies the position of the leftmost tab in Linux and isn't even orange) being moved to the same location as where Chrome has it. But there still seems to be a lot of wasted space in the titlebar of the Linux theme.

I remember reading that this is because certain opendesktop UI guidelines (can't remember which one) prohibit apps from encroaching on the window chrome. But Chrome doesn't care and puts tabs at the top of the chrome anyway, and this is quite useful because you can just push the mouse to the top edge of the screen to click on a tab. With a thick titlebar occupying the edge, on the other hand, you need to aim more carefully.